diff --git a/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java b/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java
index 826a93680d..98b88e35a9 100644
--- a/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/ResultImpl.java
@@ -67,9 +67,9 @@ import org.jooq.Field;
 import org.jooq.Record;
 import org.jooq.RecordHandler;
 import org.jooq.RecordMapper;
+import org.jooq.RecordType;
 import org.jooq.Result;
 import org.jooq.Row;
-import org.jooq.RecordType;
 import org.jooq.Table;
 import org.jooq.exception.InvalidResultException;
 import org.jooq.tools.Convert;
@@ -800,10 +800,10 @@ class ResultImpl<R extends Record> implements Result<R>, AttachableInternal {
         for (R record : this) {
 
             @SuppressWarnings({ "rawtypes", "unchecked" })
-            Record key = new RecordImpl(keys);
+            RecordImpl key = new RecordImpl(keys);
 
             for (Field<?> field : keys) {
-                Utils.setValue(key, field, record, field);
+                Utils.copyValue(key, field, record, field);
             }
 
             if (map.put(key, record) != null) {
@@ -909,10 +909,10 @@ class ResultImpl<R extends Record> implements Result<R>, AttachableInternal {
         for (R record : this) {
 
             @SuppressWarnings({ "rawtypes", "unchecked" })
-            Record key = new RecordImpl(keys);
+            RecordImpl key = new RecordImpl(keys);
 
             for (Field<?> field : keys) {
-                Utils.setValue(key, field, record, field);
+                Utils.copyValue(key, field, record, field);
             }
 
             Result<R> result = map.get(key);
@@ -961,10 +961,10 @@ class ResultImpl<R extends Record> implements Result<R>, AttachableInternal {
         for (R record : this) {
 
             @SuppressWarnings({ "rawtypes", "unchecked" })
-            Record key = new RecordImpl(keys);
+            RecordImpl key = new RecordImpl(keys);
 
             for (Field<?> field : keys) {
-                Utils.setValue(key, field, record, field);
+                Utils.copyValue(key, field, record, field);
             }
 
             List<E> list = map.get(key);
diff --git a/jOOQ/src/main/java/org/jooq/impl/Utils.java b/jOOQ/src/main/java/org/jooq/impl/Utils.java
index 58a3199c9b..b281691a63 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Utils.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Utils.java
@@ -1171,6 +1171,19 @@ final class Utils {
         target.setValue(targetField, targetField.getDataType().convert(value));
     }
 
+    /**
+     * [#2591] Type-safely copy a value from one record to another, preserving flags.
+     */
+    static final <T> void copyValue(AbstractRecord target, Field<T> targetField, Record source, Field<?> sourceField) {
+        Value<T> value = new Value<T>(
+            targetField.getDataType().convert(source.getValue(sourceField)),
+            targetField.getDataType().convert(source.original(sourceField)),
+            source.changed(sourceField)
+        );
+
+        target.setValue(targetField, value);
+    }
+
     /**
      * Map a {@link Schema} according to the configured {@link org.jooq.SchemaMapping}
      */
diff --git a/jOOQ/src/main/java/org/jooq/impl/Value.java b/jOOQ/src/main/java/org/jooq/impl/Value.java
index 0886a5382e..5fe9d237b7 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Value.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Value.java
@@ -51,8 +51,13 @@ class Value<T> implements Serializable {
     private boolean           isChanged;
 
     Value(T value) {
-        this.original = value;
+        this(value, value, false);
+    }
+
+    Value(T value, T original, boolean isChanged) {
         this.value = value;
+        this.original = original;
+        this.isChanged = isChanged;
     }
 
     final T getValue() {