diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
index bfc6892242..1585e9b1ec 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
@@ -2488,7 +2488,6 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
 
 
 
-
             ;
 
         List<Condition> semiAntiJoinPredicates = null;
@@ -2606,7 +2605,8 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
         // --------------------------
         context.start(SELECT_GROUP_BY);
 
-        if (!getGroupBy().isEmpty() || getHaving().hasWhere() && NO_IMPLICIT_GROUP_BY_ON_HAVING.contains(context.dialect())) {
+        ConditionProviderImpl having0 = getHaving(context);
+        if (!getGroupBy().isEmpty() || having0.hasWhere() && NO_IMPLICIT_GROUP_BY_ON_HAVING.contains(context.dialect())) {
             context.formatSeparator()
                    .visit(K_GROUP_BY);
 
@@ -2641,11 +2641,11 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
         // -------------
         context.start(SELECT_HAVING);
 
-        if (getHaving().hasWhere())
+        if (having0.hasWhere())
             context.formatSeparator()
                    .visit(K_HAVING)
                    .sql(' ')
-                   .visit(getHaving());
+                   .visit(having0);
 
         context.end(SELECT_HAVING);
 
@@ -4272,7 +4272,8 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
         // - There is a SEEK clause (obvious case)
         // - There are no unions (union is nested in derived table
         //   and SEEK predicate is applied outside). See [#7459]
-        if (!getOrderBy().isEmpty() && !getSeek().isEmpty() && unionOp.isEmpty())
+        //   [#15820] We're not grouping
+        if (!isGrouping() && !getOrderBy().isEmpty() && !getSeek().isEmpty() && unionOp.isEmpty())
             result.addConditions(getSeekCondition(ctx));
 
         // [#13639] Add JOIN predicates generated by path expressions in FROM clause.
@@ -4405,12 +4406,32 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
 
 
 
+    final boolean isGrouping() {
+
+        // [#15820] TODO: The presence of any aggregate function also implies at least GROUP BY ()
+        return !groupBy.isEmpty() || having.hasWhere();
+    }
+
     final GroupFieldList getGroupBy() {
         return groupBy;
     }
 
-    final ConditionProviderImpl getHaving() {
-        return having;
+    final ConditionProviderImpl getHaving(Context<?> ctx) {
+        ConditionProviderImpl result = new ConditionProviderImpl();
+
+        if (having.hasWhere())
+            result.addConditions(having.getWhere());
+
+        // Apply SEEK predicates in the WHERE clause only if:
+        // - There is an ORDER BY clause (SEEK is non-deterministic)
+        // - There is a SEEK clause (obvious case)
+        // - There are no unions (union is nested in derived table
+        //   and SEEK predicate is applied outside). See [#7459]
+        //   [#15820] We're not grouping
+        if (isGrouping() && !getOrderBy().isEmpty() && !getSeek().isEmpty() && unionOp.isEmpty())
+            result.addConditions(getSeekCondition(ctx));
+
+        return result;
     }
 
     final ConditionProviderImpl getQualify() {
@@ -4646,32 +4667,32 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
 
     @Override
     public final void addHaving(Condition conditions) {
-        getHaving().addConditions(conditions);
+        having.addConditions(conditions);
     }
 
     @Override
     public final void addHaving(Condition... conditions) {
-        getHaving().addConditions(conditions);
+        having.addConditions(conditions);
     }
 
     @Override
     public final void addHaving(Collection<? extends Condition> conditions) {
-        getHaving().addConditions(conditions);
+        having.addConditions(conditions);
     }
 
     @Override
     public final void addHaving(Operator operator, Condition conditions) {
-        getHaving().addConditions(operator, conditions);
+        having.addConditions(operator, conditions);
     }
 
     @Override
     public final void addHaving(Operator operator, Condition... conditions) {
-        getHaving().addConditions(operator, conditions);
+        having.addConditions(operator, conditions);
     }
 
     @Override
     public final void addHaving(Operator operator, Collection<? extends Condition> conditions) {
-        getHaving().addConditions(operator, conditions);
+        having.addConditions(operator, conditions);
     }
 
     @Override