diff --git a/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java b/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
index 1a4e5ef9cc..0e529ef204 100644
--- a/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
@@ -251,7 +251,7 @@ implements
 
 
     private static final Set<SQLDialect> NO_SUPPORT_MULTI                        = SQLDialect.supportedBy(HSQLDB);
-    private static final Set<SQLDialect> REQUIRE_NEGATION                        = SQLDialect.supportedBy(H2);
+    private static final Set<SQLDialect> REQUIRE_NEGATION                        = SQLDialect.supportedBy(H2, HSQLDB);
     private static final Set<SQLDialect> NO_SUPPORT_CONDITION_AFTER_NO_CONDITION = SQLDialect.supportedBy(FIREBIRD);
 
     private final WithImpl               with;