diff --git a/jOOQ/src/main/java/org/jooq/AggregateFunction.java b/jOOQ/src/main/java/org/jooq/AggregateFunction.java
index b01e146a94..7ac8520d48 100644
--- a/jOOQ/src/main/java/org/jooq/AggregateFunction.java
+++ b/jOOQ/src/main/java/org/jooq/AggregateFunction.java
@@ -53,17 +53,17 @@
  */
 package org.jooq;
 
-import static org.jooq.SQLDialect.CUBRID;
-import static org.jooq.SQLDialect.DB2;
-import static org.jooq.SQLDialect.ORACLE;
-import static org.jooq.SQLDialect.POSTGRES;
-import static org.jooq.SQLDialect.SQLSERVER;
-import static org.jooq.SQLDialect.SYBASE;
-
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
+import static org.jooq.SQLDialect.CUBRID;
+import static org.jooq.SQLDialect.DB2;
+import static org.jooq.SQLDialect.ORACLE;
+import static org.jooq.SQLDialect.POSTGRES;
+import static org.jooq.SQLDialect.SQLSERVER;
+import static org.jooq.SQLDialect.SYBASE;
+
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
 
 /**
  * An aggregate function is a special field that is usually used in a
@@ -148,7 +148,7 @@ public interface AggregateFunction<T> extends Field<T>, WindowOverStep<T> {
         name = "KEEP DENSE_RANK FIRST ORDER BY",
         args = "SortField+"
     )
-    WindowBeforeOverStep<T> keepDenseRankFirstOrderBy(Collection<SortField<?>> fields);
+    WindowBeforeOverStep<T> keepDenseRankFirstOrderBy(Collection<? extends SortField<?>> fields);
 
     /**
      * Restrict this aggregate function to <code>FIRST</code> values
@@ -199,5 +199,5 @@ public interface AggregateFunction<T> extends Field<T>, WindowOverStep<T> {
         name = "KEEP DENSE_RANK LAST ORDER BY",
         args = "SortField+"
     )
-    WindowBeforeOverStep<T> keepDenseRankLastOrderBy(Collection<SortField<?>> fields);
+    WindowBeforeOverStep<T> keepDenseRankLastOrderBy(Collection<? extends SortField<?>> fields);
 }
diff --git a/jOOQ/src/main/java/org/jooq/ConditionProvider.java b/jOOQ/src/main/java/org/jooq/ConditionProvider.java
index 93e0ba8d83..d9b43ffed2 100644
--- a/jOOQ/src/main/java/org/jooq/ConditionProvider.java
+++ b/jOOQ/src/main/java/org/jooq/ConditionProvider.java
@@ -83,7 +83,7 @@ public interface ConditionProvider {
      * @param conditions The condition
      */
     @Support
-    void addConditions(Collection<Condition> conditions);
+    void addConditions(Collection<? extends Condition> conditions);
 
     /**
      * Adds new conditions to the query, connecting them to existing
@@ -101,6 +101,6 @@ public interface ConditionProvider {
      * @param conditions The condition
      */
     @Support
-    void addConditions(Operator operator, Collection<Condition> conditions);
+    void addConditions(Operator operator, Collection<? extends Condition> conditions);
 
 }
diff --git a/jOOQ/src/main/java/org/jooq/DeleteQuery.java b/jOOQ/src/main/java/org/jooq/DeleteQuery.java
index 45aa829674..1478b352a7 100644
--- a/jOOQ/src/main/java/org/jooq/DeleteQuery.java
+++ b/jOOQ/src/main/java/org/jooq/DeleteQuery.java
@@ -81,7 +81,7 @@ public interface DeleteQuery<R extends Record> extends ConditionProvider, Delete
      */
     @Override
     @Support
-    void addConditions(Collection<Condition> conditions);
+    void addConditions(Collection<? extends Condition> conditions);
 
     /**
      * {@inheritDoc}
@@ -95,6 +95,6 @@ public interface DeleteQuery<R extends Record> extends ConditionProvider, Delete
      */
     @Override
     @Support
-    void addConditions(Operator operator, Collection<Condition> conditions);
+    void addConditions(Operator operator, Collection<? extends Condition> conditions);
 
 }
diff --git a/jOOQ/src/main/java/org/jooq/DeleteWhereStep.java b/jOOQ/src/main/java/org/jooq/DeleteWhereStep.java
index 3eebd80541..b6563b8b3a 100644
--- a/jOOQ/src/main/java/org/jooq/DeleteWhereStep.java
+++ b/jOOQ/src/main/java/org/jooq/DeleteWhereStep.java
@@ -53,11 +53,11 @@
  */
 package org.jooq;
 
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
-import org.jooq.impl.DSL;
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
+import org.jooq.impl.DSL;
 
 /**
  * This type is used for the {@link Delete}'s DSL API.
@@ -93,7 +93,7 @@ public interface DeleteWhereStep<R extends Record> extends DeleteFinalStep<R> {
         name = "WHERE",
         args = "Condition+"
     )
-    DeleteConditionStep<R> where(Collection<Condition> conditions);
+    DeleteConditionStep<R> where(Collection<? extends Condition> conditions);
 
     /**
      * Add conditions to the query.
diff --git a/jOOQ/src/main/java/org/jooq/GroupConcatOrderByStep.java b/jOOQ/src/main/java/org/jooq/GroupConcatOrderByStep.java
index e1c766e636..50f9b1cf3e 100644
--- a/jOOQ/src/main/java/org/jooq/GroupConcatOrderByStep.java
+++ b/jOOQ/src/main/java/org/jooq/GroupConcatOrderByStep.java
@@ -53,22 +53,22 @@
  */
 package org.jooq;
 
-import static org.jooq.SQLDialect.CUBRID;
-import static org.jooq.SQLDialect.DB2;
-import static org.jooq.SQLDialect.H2;
-import static org.jooq.SQLDialect.HSQLDB;
-import static org.jooq.SQLDialect.MARIADB;
-import static org.jooq.SQLDialect.MYSQL;
-import static org.jooq.SQLDialect.ORACLE11G;
-import static org.jooq.SQLDialect.ORACLE12C;
-import static org.jooq.SQLDialect.POSTGRES;
-import static org.jooq.SQLDialect.SYBASE;
-
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
-import org.jooq.impl.DSL;
+import static org.jooq.SQLDialect.CUBRID;
+import static org.jooq.SQLDialect.DB2;
+import static org.jooq.SQLDialect.H2;
+import static org.jooq.SQLDialect.HSQLDB;
+import static org.jooq.SQLDialect.MARIADB;
+import static org.jooq.SQLDialect.MYSQL;
+import static org.jooq.SQLDialect.ORACLE11G;
+import static org.jooq.SQLDialect.ORACLE12C;
+import static org.jooq.SQLDialect.POSTGRES;
+import static org.jooq.SQLDialect.SYBASE;
+
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
+import org.jooq.impl.DSL;
 
 
 /**
@@ -108,5 +108,5 @@ public interface GroupConcatOrderByStep extends GroupConcatSeparatorStep {
         name = "ORDER BY",
         args = "SortField+"
     )
-    GroupConcatSeparatorStep orderBy(Collection<SortField<?>> fields);
+    GroupConcatSeparatorStep orderBy(Collection<? extends SortField<?>> fields);
 }
diff --git a/jOOQ/src/main/java/org/jooq/OrderedAggregateFunction.java b/jOOQ/src/main/java/org/jooq/OrderedAggregateFunction.java
index e300cc63d2..eadae032e1 100644
--- a/jOOQ/src/main/java/org/jooq/OrderedAggregateFunction.java
+++ b/jOOQ/src/main/java/org/jooq/OrderedAggregateFunction.java
@@ -53,13 +53,13 @@
  */
 package org.jooq;
 
-import static org.jooq.SQLDialect.ORACLE11G;
-import static org.jooq.SQLDialect.ORACLE12C;
-
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
+import static org.jooq.SQLDialect.ORACLE11G;
+import static org.jooq.SQLDialect.ORACLE12C;
+
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
 
 /**
  * An ordered aggregate function.
@@ -121,5 +121,5 @@ public interface OrderedAggregateFunction<T> {
         args = "SortField+",
         to = "OrderedAggregateFunction"
     )
-    AggregateFunction<T> withinGroupOrderBy(Collection<SortField<?>> fields);
+    AggregateFunction<T> withinGroupOrderBy(Collection<? extends SortField<?>> fields);
 }
diff --git a/jOOQ/src/main/java/org/jooq/SelectForUpdateOfStep.java b/jOOQ/src/main/java/org/jooq/SelectForUpdateOfStep.java
index 74583eec86..522860b09c 100644
--- a/jOOQ/src/main/java/org/jooq/SelectForUpdateOfStep.java
+++ b/jOOQ/src/main/java/org/jooq/SelectForUpdateOfStep.java
@@ -53,20 +53,20 @@
  */
 package org.jooq;
 
-import static org.jooq.SQLDialect.DB2;
-import static org.jooq.SQLDialect.DERBY;
-import static org.jooq.SQLDialect.FIREBIRD;
-import static org.jooq.SQLDialect.H2;
-import static org.jooq.SQLDialect.HSQLDB;
-import static org.jooq.SQLDialect.INGRES;
-import static org.jooq.SQLDialect.ORACLE;
-import static org.jooq.SQLDialect.POSTGRES;
-import static org.jooq.SQLDialect.SYBASE;
-
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
+import static org.jooq.SQLDialect.DB2;
+import static org.jooq.SQLDialect.DERBY;
+import static org.jooq.SQLDialect.FIREBIRD;
+import static org.jooq.SQLDialect.H2;
+import static org.jooq.SQLDialect.HSQLDB;
+import static org.jooq.SQLDialect.INGRES;
+import static org.jooq.SQLDialect.ORACLE;
+import static org.jooq.SQLDialect.POSTGRES;
+import static org.jooq.SQLDialect.SYBASE;
+
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
 
 /**
  * This type is used for the {@link Select}'s DSL API when selecting generic
@@ -139,7 +139,7 @@ public interface SelectForUpdateOfStep<R extends Record> extends SelectForUpdate
         name = "OF",
         args = "Field+"
     )
-    SelectForUpdateWaitStep<R> of(Collection<Field<?>> fields);
+    SelectForUpdateWaitStep<R> of(Collection<? extends Field<?>> fields);
 
     /**
      * Add an <code>OF</code> clause to the <code>FOR UPDATE</code> clause at
diff --git a/jOOQ/src/main/java/org/jooq/SelectHavingStep.java b/jOOQ/src/main/java/org/jooq/SelectHavingStep.java
index b6f639feb4..a3c3229611 100644
--- a/jOOQ/src/main/java/org/jooq/SelectHavingStep.java
+++ b/jOOQ/src/main/java/org/jooq/SelectHavingStep.java
@@ -122,7 +122,7 @@ public interface SelectHavingStep<R extends Record> extends SelectOrderByStep<R>
         name = "HAVING",
         args = "Condition+"
     )
-    SelectHavingConditionStep<R> having(Collection<Condition> conditions);
+    SelectHavingConditionStep<R> having(Collection<? extends Condition> conditions);
 
     /**
      * Add a <code>HAVING</code> clause to the query.
diff --git a/jOOQ/src/main/java/org/jooq/SelectOrderByStep.java b/jOOQ/src/main/java/org/jooq/SelectOrderByStep.java
index 00a47f2533..b765787e08 100644
--- a/jOOQ/src/main/java/org/jooq/SelectOrderByStep.java
+++ b/jOOQ/src/main/java/org/jooq/SelectOrderByStep.java
@@ -134,7 +134,7 @@ public interface SelectOrderByStep<R extends Record> extends SelectLimitStep<R>
         name = "ORDER BY",
         args = "SortField+"
     )
-    SelectLimitStep<R> orderBy(Collection<SortField<?>> fields);
+    SelectLimitStep<R> orderBy(Collection<? extends SortField<?>> fields);
 
     /**
      * Add an <code>ORDER BY</code> clause to the query
@@ -192,7 +192,7 @@ public interface SelectOrderByStep<R extends Record> extends SelectLimitStep<R>
         name = "ORDER SIBLINGS BY",
         args = "SortField+"
     )
-    SelectLimitStep<R> orderSiblingsBy(Collection<SortField<?>> fields);
+    SelectLimitStep<R> orderSiblingsBy(Collection<? extends SortField<?>> fields);
 
     /**
      * Add an <code>ORDER SIBLINGS BY</code> clause to the query
diff --git a/jOOQ/src/main/java/org/jooq/SelectQuery.java b/jOOQ/src/main/java/org/jooq/SelectQuery.java
index 7cd742d1c0..2052d94e5a 100644
--- a/jOOQ/src/main/java/org/jooq/SelectQuery.java
+++ b/jOOQ/src/main/java/org/jooq/SelectQuery.java
@@ -257,7 +257,7 @@ public interface SelectQuery<R extends Record> extends Select<R>, ConditionProvi
      * @param conditions The condition
      */
     @Support
-    void addHaving(Collection<Condition> conditions);
+    void addHaving(Collection<? extends Condition> conditions);
 
     /**
      * Adds new conditions to the having clause of query, connecting them to
@@ -279,7 +279,7 @@ public interface SelectQuery<R extends Record> extends Select<R>, ConditionProvi
      * @param conditions The condition
      */
     @Support
-    void addHaving(Operator operator, Collection<Condition> conditions);
+    void addHaving(Operator operator, Collection<? extends Condition> conditions);
 
     /**
      * Add an Oracle-style hint to the select clause.
@@ -380,7 +380,7 @@ public interface SelectQuery<R extends Record> extends Select<R>, ConditionProvi
      */
     @Override
     @Support
-    void addConditions(Collection<Condition> conditions);
+    void addConditions(Collection<? extends Condition> conditions);
 
     /**
      * {@inheritDoc}
@@ -394,7 +394,7 @@ public interface SelectQuery<R extends Record> extends Select<R>, ConditionProvi
      */
     @Override
     @Support
-    void addConditions(Operator operator, Collection<Condition> conditions);
+    void addConditions(Operator operator, Collection<? extends Condition> conditions);
 
     /**
      * Adds ordering fields, ordering by the default sort order
@@ -418,7 +418,7 @@ public interface SelectQuery<R extends Record> extends Select<R>, ConditionProvi
      * @param fields The ordering fields
      */
     @Support
-    void addOrderBy(Collection<SortField<?>> fields);
+    void addOrderBy(Collection<? extends SortField<?>> fields);
 
     /**
      * Adds ordering fields
diff --git a/jOOQ/src/main/java/org/jooq/SelectWhereStep.java b/jOOQ/src/main/java/org/jooq/SelectWhereStep.java
index 49febc2ca4..661df7c16f 100644
--- a/jOOQ/src/main/java/org/jooq/SelectWhereStep.java
+++ b/jOOQ/src/main/java/org/jooq/SelectWhereStep.java
@@ -122,7 +122,7 @@ public interface SelectWhereStep<R extends Record> extends SelectConnectByStep<R
         name = "WHERE",
         args = "Condition+"
     )
-    SelectConditionStep<R> where(Collection<Condition> conditions);
+    SelectConditionStep<R> where(Collection<? extends Condition> conditions);
 
     /**
      * Add a <code>WHERE</code> clause to the query.
diff --git a/jOOQ/src/main/java/org/jooq/UpdateQuery.java b/jOOQ/src/main/java/org/jooq/UpdateQuery.java
index d82d43a46a..da02f6b35e 100644
--- a/jOOQ/src/main/java/org/jooq/UpdateQuery.java
+++ b/jOOQ/src/main/java/org/jooq/UpdateQuery.java
@@ -403,7 +403,7 @@ public interface UpdateQuery<R extends Record> extends StoreQuery<R>, ConditionP
      */
     @Override
     @Support
-    void addConditions(Collection<Condition> conditions);
+    void addConditions(Collection<? extends Condition> conditions);
 
     /**
      * {@inheritDoc}
@@ -417,7 +417,7 @@ public interface UpdateQuery<R extends Record> extends StoreQuery<R>, ConditionP
      */
     @Override
     @Support
-    void addConditions(Operator operator, Collection<Condition> conditions);
+    void addConditions(Operator operator, Collection<? extends Condition> conditions);
 
     // ------------------------------------------------------------------------
     // XXX: Methods for the UPDATE .. RETURNING syntax
diff --git a/jOOQ/src/main/java/org/jooq/UpdateWhereStep.java b/jOOQ/src/main/java/org/jooq/UpdateWhereStep.java
index 0874eb734a..828a3b7b14 100644
--- a/jOOQ/src/main/java/org/jooq/UpdateWhereStep.java
+++ b/jOOQ/src/main/java/org/jooq/UpdateWhereStep.java
@@ -53,11 +53,11 @@
  */
 package org.jooq;
 
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
-import org.jooq.impl.DSL;
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
+import org.jooq.impl.DSL;
 
 /**
  * This type is used for the {@link Update}'s DSL API.
@@ -95,7 +95,7 @@ public interface UpdateWhereStep<R extends Record> extends UpdateFinalStep<R>, U
         name = "WHERE",
         args = "Condition+"
     )
-    UpdateConditionStep<R> where(Collection<Condition> conditions);
+    UpdateConditionStep<R> where(Collection<? extends Condition> conditions);
 
     /**
      * Add conditions to the query
diff --git a/jOOQ/src/main/java/org/jooq/WindowOrderByStep.java b/jOOQ/src/main/java/org/jooq/WindowOrderByStep.java
index d2a09f9cba..ef62430cec 100644
--- a/jOOQ/src/main/java/org/jooq/WindowOrderByStep.java
+++ b/jOOQ/src/main/java/org/jooq/WindowOrderByStep.java
@@ -53,17 +53,17 @@
  */
 package org.jooq;
 
-import static org.jooq.SQLDialect.CUBRID;
-import static org.jooq.SQLDialect.DB2;
-import static org.jooq.SQLDialect.ORACLE;
-import static org.jooq.SQLDialect.POSTGRES;
-import static org.jooq.SQLDialect.SQLSERVER;
-import static org.jooq.SQLDialect.SYBASE;
-
-import java.util.Collection;
-
-import org.jooq.api.annotation.State;
-import org.jooq.api.annotation.Transition;
+import static org.jooq.SQLDialect.CUBRID;
+import static org.jooq.SQLDialect.DB2;
+import static org.jooq.SQLDialect.ORACLE;
+import static org.jooq.SQLDialect.POSTGRES;
+import static org.jooq.SQLDialect.SQLSERVER;
+import static org.jooq.SQLDialect.SYBASE;
+
+import java.util.Collection;
+
+import org.jooq.api.annotation.State;
+import org.jooq.api.annotation.Transition;
 
 /**
  * This type is used for the window function DSL API.
@@ -112,5 +112,5 @@ public interface WindowOrderByStep<T> extends WindowFinalStep<T> {
         name = "ORDER BY",
         args = "SortField+"
     )
-    WindowRowsStep<T> orderBy(Collection<SortField<?>> fields);
+    WindowRowsStep<T> orderBy(Collection<? extends SortField<?>> fields);
 }
diff --git a/jOOQ/src/main/java/org/jooq/impl/ConditionProviderImpl.java b/jOOQ/src/main/java/org/jooq/impl/ConditionProviderImpl.java
index 10dcb6b6cc..08c8a2ec3b 100644
--- a/jOOQ/src/main/java/org/jooq/impl/ConditionProviderImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/ConditionProviderImpl.java
@@ -101,7 +101,7 @@ class ConditionProviderImpl extends AbstractQueryPart implements ConditionProvid
     }
 
     @Override
-    public final void addConditions(Collection<Condition> conditions) {
+    public final void addConditions(Collection<? extends Condition> conditions) {
         addConditions(Operator.AND, conditions);
     }
 
@@ -111,7 +111,7 @@ class ConditionProviderImpl extends AbstractQueryPart implements ConditionProvid
     }
 
     @Override
-    public final void addConditions(Operator operator, Collection<Condition> conditions) {
+    public final void addConditions(Operator operator, Collection<? extends Condition> conditions) {
         if (!conditions.isEmpty()) {
             Condition c;
 
diff --git a/jOOQ/src/main/java/org/jooq/impl/DeleteImpl.java b/jOOQ/src/main/java/org/jooq/impl/DeleteImpl.java
index c1e356fe41..091299a5a8 100644
--- a/jOOQ/src/main/java/org/jooq/impl/DeleteImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/DeleteImpl.java
@@ -53,22 +53,22 @@
  */
 package org.jooq.impl;
 
-import static org.jooq.impl.DSL.condition;
-import static org.jooq.impl.DSL.exists;
-import static org.jooq.impl.DSL.notExists;
-
-import java.util.Collection;
-
-import org.jooq.Condition;
-import org.jooq.Configuration;
-import org.jooq.DeleteConditionStep;
-import org.jooq.DeleteWhereStep;
-import org.jooq.Field;
-import org.jooq.Operator;
-import org.jooq.QueryPart;
-import org.jooq.Record;
-import org.jooq.Select;
-import org.jooq.Table;
+import static org.jooq.impl.DSL.condition;
+import static org.jooq.impl.DSL.exists;
+import static org.jooq.impl.DSL.notExists;
+
+import java.util.Collection;
+
+import org.jooq.Condition;
+import org.jooq.Configuration;
+import org.jooq.DeleteConditionStep;
+import org.jooq.DeleteWhereStep;
+import org.jooq.Field;
+import org.jooq.Operator;
+import org.jooq.QueryPart;
+import org.jooq.Record;
+import org.jooq.Select;
+import org.jooq.Table;
 
 /**
  * @author Lukas Eder
@@ -97,7 +97,7 @@ class DeleteImpl<R extends Record>
     }
 
     @Override
-    public final DeleteImpl<R> where(Collection<Condition> conditions) {
+    public final DeleteImpl<R> where(Collection<? extends Condition> conditions) {
         getDelegate().addConditions(conditions);
         return this;
     }
diff --git a/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java
index 5e73505d38..4bd0a8b0f6 100644
--- a/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java
@@ -101,7 +101,7 @@ class DeleteQueryImpl<R extends Record> extends AbstractQuery implements DeleteQ
     }
 
     @Override
-    public final void addConditions(Collection<Condition> conditions) {
+    public final void addConditions(Collection<? extends Condition> conditions) {
         condition.addConditions(conditions);
     }
 
@@ -116,7 +116,7 @@ class DeleteQueryImpl<R extends Record> extends AbstractQuery implements DeleteQ
     }
 
     @Override
-    public final void addConditions(Operator operator, Collection<Condition> conditions) {
+    public final void addConditions(Operator operator, Collection<? extends Condition> conditions) {
         condition.addConditions(operator, conditions);
     }
 
diff --git a/jOOQ/src/main/java/org/jooq/impl/Function.java b/jOOQ/src/main/java/org/jooq/impl/Function.java
index 3945471bbe..fab85aa86f 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Function.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Function.java
@@ -513,7 +513,7 @@ class Function<T> extends AbstractField<T> implements
     }
 
     @Override
-    public final AggregateFunction<T> withinGroupOrderBy(Collection<SortField<?>> fields) {
+    public final AggregateFunction<T> withinGroupOrderBy(Collection<? extends SortField<?>> fields) {
         withinGroupOrderBy.addAll(fields);
         return this;
     }
@@ -531,7 +531,7 @@ class Function<T> extends AbstractField<T> implements
     }
 
     @Override
-    public final WindowBeforeOverStep<T> keepDenseRankFirstOrderBy(Collection<SortField<?>> fields) {
+    public final WindowBeforeOverStep<T> keepDenseRankFirstOrderBy(Collection<? extends SortField<?>> fields) {
         first = true;
         keepDenseRankOrderBy.addAll(fields);
         return this;
@@ -549,7 +549,7 @@ class Function<T> extends AbstractField<T> implements
     }
 
     @Override
-    public final WindowBeforeOverStep<T> keepDenseRankLastOrderBy(Collection<SortField<?>> fields) {
+    public final WindowBeforeOverStep<T> keepDenseRankLastOrderBy(Collection<? extends SortField<?>> fields) {
         keepDenseRankOrderBy.addAll(fields);
         return this;
     }
@@ -600,7 +600,7 @@ class Function<T> extends AbstractField<T> implements
     }
 
     @Override
-    public final WindowRowsStep<T> orderBy(Collection<SortField<?>> fields) {
+    public final WindowRowsStep<T> orderBy(Collection<? extends SortField<?>> fields) {
         orderBy.addAll(fields);
         return this;
     }
diff --git a/jOOQ/src/main/java/org/jooq/impl/GroupConcat.java b/jOOQ/src/main/java/org/jooq/impl/GroupConcat.java
index 7243cd232a..13088779bf 100644
--- a/jOOQ/src/main/java/org/jooq/impl/GroupConcat.java
+++ b/jOOQ/src/main/java/org/jooq/impl/GroupConcat.java
@@ -53,19 +53,19 @@
  */
 package org.jooq.impl;
 
-import static org.jooq.impl.DSL.inline;
-
-import java.util.Arrays;
-import java.util.Collection;
-
-import org.jooq.AggregateFunction;
-import org.jooq.Configuration;
-import org.jooq.Field;
-import org.jooq.GroupConcatOrderByStep;
-import org.jooq.GroupConcatSeparatorStep;
-import org.jooq.SortField;
-import org.jooq.WindowBeforeOverStep;
-import org.jooq.WindowPartitionByStep;
+import static org.jooq.impl.DSL.inline;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import org.jooq.AggregateFunction;
+import org.jooq.Configuration;
+import org.jooq.Field;
+import org.jooq.GroupConcatOrderByStep;
+import org.jooq.GroupConcatSeparatorStep;
+import org.jooq.SortField;
+import org.jooq.WindowBeforeOverStep;
+import org.jooq.WindowPartitionByStep;
 
 /**
  * @author Lukas Eder
@@ -120,7 +120,7 @@ class GroupConcat extends AbstractFunction<String> implements GroupConcatOrderBy
     }
 
     @Override
-    public final WindowBeforeOverStep<String> keepDenseRankFirstOrderBy(Collection<SortField<?>> fields) {
+    public final WindowBeforeOverStep<String> keepDenseRankFirstOrderBy(Collection<? extends SortField<?>> fields) {
         throw new UnsupportedOperationException("KEEP() not supported on GROUP_CONCAT aggregate function");
     }
 
@@ -135,7 +135,7 @@ class GroupConcat extends AbstractFunction<String> implements GroupConcatOrderBy
     }
 
     @Override
-    public final WindowBeforeOverStep<String> keepDenseRankLastOrderBy(Collection<SortField<?>> fields) {
+    public final WindowBeforeOverStep<String> keepDenseRankLastOrderBy(Collection<? extends SortField<?>> fields) {
         throw new UnsupportedOperationException("KEEP() not supported on GROUP_CONCAT aggregate function");
     }
 
@@ -163,7 +163,7 @@ class GroupConcat extends AbstractFunction<String> implements GroupConcatOrderBy
     }
 
     @Override
-    public final GroupConcatSeparatorStep orderBy(Collection<SortField<?>> fields) {
+    public final GroupConcatSeparatorStep orderBy(Collection<? extends SortField<?>> fields) {
         orderBy.addAll(fields);
         return this;
     }
diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java
index 4dbed9c6a0..c3b6936225 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java
@@ -244,7 +244,7 @@ class SelectImpl<R extends Record> extends AbstractDelegatingQuery<Select<R>> im
     }
 
     @Override
-    public final SelectImpl<R> where(Collection<Condition> conditions) {
+    public final SelectImpl<R> where(Collection<? extends Condition> conditions) {
         conditionStep = ConditionStep.WHERE;
         getQuery().addConditions(conditions);
         return this;
@@ -506,7 +506,7 @@ class SelectImpl<R extends Record> extends AbstractDelegatingQuery<Select<R>> im
     }
 
     @Override
-    public final SelectImpl<R> orderBy(Collection<SortField<?>> fields) {
+    public final SelectImpl<R> orderBy(Collection<? extends SortField<?>> fields) {
         getQuery().addOrderBy(fields);
         return this;
     }
@@ -532,7 +532,7 @@ class SelectImpl<R extends Record> extends AbstractDelegatingQuery<Select<R>> im
     }
 
     @Override
-    public final SelectImpl<R> orderSiblingsBy(Collection<SortField<?>> fields) {
+    public final SelectImpl<R> orderSiblingsBy(Collection<? extends SortField<?>> fields) {
         getQuery().addOrderBy(fields);
         getQuery().setOrderBySiblings(true);
         return this;
@@ -622,7 +622,7 @@ class SelectImpl<R extends Record> extends AbstractDelegatingQuery<Select<R>> im
     }
 
     @Override
-    public final SelectImpl<R> of(Collection<Field<?>> fields) {
+    public final SelectImpl<R> of(Collection<? extends Field<?>> fields) {
         getQuery().setForUpdateOf(fields);
         return this;
     }
@@ -685,7 +685,7 @@ class SelectImpl<R extends Record> extends AbstractDelegatingQuery<Select<R>> im
     }
 
     @Override
-    public final SelectImpl<R> having(Collection<Condition> conditions) {
+    public final SelectImpl<R> having(Collection<? extends Condition> conditions) {
         conditionStep = ConditionStep.HAVING;
         getQuery().addHaving(conditions);
         return this;
diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
index 54b29fa841..4fe5202088 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
@@ -941,7 +941,7 @@ class SelectQueryImpl<R extends Record> extends AbstractSelect<R> implements Sel
     }
 
     @Override
-    public final void addOrderBy(Collection<SortField<?>> fields) {
+    public final void addOrderBy(Collection<? extends SortField<?>> fields) {
         getOrderBy().addAll(fields);
     }
 
@@ -977,7 +977,7 @@ class SelectQueryImpl<R extends Record> extends AbstractSelect<R> implements Sel
     }
 
     @Override
-    public final void addConditions(Collection<Condition> conditions) {
+    public final void addConditions(Collection<? extends Condition> conditions) {
         condition.addConditions(conditions);
     }
 
@@ -987,7 +987,7 @@ class SelectQueryImpl<R extends Record> extends AbstractSelect<R> implements Sel
     }
 
     @Override
-    public final void addConditions(Operator operator, Collection<Condition> conditions) {
+    public final void addConditions(Operator operator, Collection<? extends Condition> conditions) {
         condition.addConditions(operator, conditions);
     }
 
@@ -1057,7 +1057,7 @@ class SelectQueryImpl<R extends Record> extends AbstractSelect<R> implements Sel
     }
 
     @Override
-    public final void addHaving(Collection<Condition> conditions) {
+    public final void addHaving(Collection<? extends Condition> conditions) {
         getHaving().addConditions(conditions);
     }
 
@@ -1067,7 +1067,7 @@ class SelectQueryImpl<R extends Record> extends AbstractSelect<R> implements Sel
     }
 
     @Override
-    public final void addHaving(Operator operator, Collection<Condition> conditions) {
+    public final void addHaving(Operator operator, Collection<? extends Condition> conditions) {
         getHaving().addConditions(operator, conditions);
     }
 
diff --git a/jOOQ/src/main/java/org/jooq/impl/UpdateImpl.java b/jOOQ/src/main/java/org/jooq/impl/UpdateImpl.java
index 4bf28e7669..955023ce97 100644
--- a/jOOQ/src/main/java/org/jooq/impl/UpdateImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/UpdateImpl.java
@@ -53,74 +53,74 @@
  */
 package org.jooq.impl;
 
-import static org.jooq.impl.DSL.condition;
-import static org.jooq.impl.DSL.exists;
-import static org.jooq.impl.DSL.notExists;
-
-import java.util.Collection;
-import java.util.Map;
-
-import javax.annotation.Generated;
-
-import org.jooq.Condition;
-import org.jooq.Configuration;
-import org.jooq.Field;
-import org.jooq.Operator;
-import org.jooq.QueryPart;
-import org.jooq.Record;
-import org.jooq.Record1;
-import org.jooq.Record10;
-import org.jooq.Record11;
-import org.jooq.Record12;
-import org.jooq.Record13;
-import org.jooq.Record14;
-import org.jooq.Record15;
-import org.jooq.Record16;
-import org.jooq.Record17;
-import org.jooq.Record18;
-import org.jooq.Record19;
-import org.jooq.Record2;
-import org.jooq.Record20;
-import org.jooq.Record21;
-import org.jooq.Record22;
-import org.jooq.Record3;
-import org.jooq.Record4;
-import org.jooq.Record5;
-import org.jooq.Record6;
-import org.jooq.Record7;
-import org.jooq.Record8;
-import org.jooq.Record9;
-import org.jooq.Result;
-import org.jooq.Row1;
-import org.jooq.Row10;
-import org.jooq.Row11;
-import org.jooq.Row12;
-import org.jooq.Row13;
-import org.jooq.Row14;
-import org.jooq.Row15;
-import org.jooq.Row16;
-import org.jooq.Row17;
-import org.jooq.Row18;
-import org.jooq.Row19;
-import org.jooq.Row2;
-import org.jooq.Row20;
-import org.jooq.Row21;
-import org.jooq.Row22;
-import org.jooq.Row3;
-import org.jooq.Row4;
-import org.jooq.Row5;
-import org.jooq.Row6;
-import org.jooq.Row7;
-import org.jooq.Row8;
-import org.jooq.Row9;
-import org.jooq.Select;
-import org.jooq.Table;
-import org.jooq.UpdateConditionStep;
-import org.jooq.UpdateQuery;
-import org.jooq.UpdateResultStep;
-import org.jooq.UpdateSetFirstStep;
-import org.jooq.UpdateSetMoreStep;
-import org.jooq.UpdateWhereStep;
+import static org.jooq.impl.DSL.condition;
+import static org.jooq.impl.DSL.exists;
+import static org.jooq.impl.DSL.notExists;
+
+import java.util.Collection;
+import java.util.Map;
+
+import javax.annotation.Generated;
+
+import org.jooq.Condition;
+import org.jooq.Configuration;
+import org.jooq.Field;
+import org.jooq.Operator;
+import org.jooq.QueryPart;
+import org.jooq.Record;
+import org.jooq.Record1;
+import org.jooq.Record10;
+import org.jooq.Record11;
+import org.jooq.Record12;
+import org.jooq.Record13;
+import org.jooq.Record14;
+import org.jooq.Record15;
+import org.jooq.Record16;
+import org.jooq.Record17;
+import org.jooq.Record18;
+import org.jooq.Record19;
+import org.jooq.Record2;
+import org.jooq.Record20;
+import org.jooq.Record21;
+import org.jooq.Record22;
+import org.jooq.Record3;
+import org.jooq.Record4;
+import org.jooq.Record5;
+import org.jooq.Record6;
+import org.jooq.Record7;
+import org.jooq.Record8;
+import org.jooq.Record9;
+import org.jooq.Result;
+import org.jooq.Row1;
+import org.jooq.Row10;
+import org.jooq.Row11;
+import org.jooq.Row12;
+import org.jooq.Row13;
+import org.jooq.Row14;
+import org.jooq.Row15;
+import org.jooq.Row16;
+import org.jooq.Row17;
+import org.jooq.Row18;
+import org.jooq.Row19;
+import org.jooq.Row2;
+import org.jooq.Row20;
+import org.jooq.Row21;
+import org.jooq.Row22;
+import org.jooq.Row3;
+import org.jooq.Row4;
+import org.jooq.Row5;
+import org.jooq.Row6;
+import org.jooq.Row7;
+import org.jooq.Row8;
+import org.jooq.Row9;
+import org.jooq.Select;
+import org.jooq.Table;
+import org.jooq.UpdateConditionStep;
+import org.jooq.UpdateQuery;
+import org.jooq.UpdateResultStep;
+import org.jooq.UpdateSetFirstStep;
+import org.jooq.UpdateSetMoreStep;
+import org.jooq.UpdateWhereStep;
 
 /**
  * A wrapper for an {@link UpdateQuery}
@@ -492,7 +492,7 @@ final class UpdateImpl<R extends Record>
     }
 
     @Override
-    public final UpdateImpl<R> where(Collection<Condition> conditions) {
+    public final UpdateImpl<R> where(Collection<? extends Condition> conditions) {
         getDelegate().addConditions(conditions);
         return this;
     }
diff --git a/jOOQ/src/main/java/org/jooq/impl/UpdateQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/UpdateQueryImpl.java
index 249880bcb2..ff42a75807 100644
--- a/jOOQ/src/main/java/org/jooq/impl/UpdateQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/UpdateQueryImpl.java
@@ -447,7 +447,7 @@ class UpdateQueryImpl<R extends Record> extends AbstractStoreQuery<R> implements
     }
 
     @Override
-    public final void addConditions(Collection<Condition> conditions) {
+    public final void addConditions(Collection<? extends Condition> conditions) {
         condition.addConditions(conditions);
     }
 
@@ -462,7 +462,7 @@ class UpdateQueryImpl<R extends Record> extends AbstractStoreQuery<R> implements
     }
 
     @Override
-    public final void addConditions(Operator operator, Collection<Condition> conditions) {
+    public final void addConditions(Operator operator, Collection<? extends Condition> conditions) {
         condition.addConditions(operator, conditions);
     }