diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java
index 2cbfe75f05ed..75273238f1de 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java
@@ -17,6 +17,9 @@ public interface RegExpLanguageHost {
   boolean characterNeedsEscaping(char c);
   boolean supportsPerl5EmbeddedComments();
   boolean supportsPossessiveQuantifiers();
+  default boolean isDuplicateGroupNamesAllowed(@NotNull RegExpGroup group) {
+    return false;
+  }
 
   /**
    * @return true, if this dialects support conditionals, i.e. the following construct: {@code (?(1)then|else)}
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java
index ef5f42894f01..c36b5909b3f3 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java
@@ -111,6 +111,11 @@ public final class RegExpLanguageHosts extends ClassExtension<RegExpLanguageHost
     return host != null && host.isValidGroupName(name, group);
   }
 
+  public boolean isDuplicateGroupNamesAllowed(@NotNull final RegExpGroup group) {
+    final RegExpLanguageHost host = findRegExpHost(group);
+    return host != null && host.isDuplicateGroupNamesAllowed(group);
+  }
+
   public boolean supportsPerl5EmbeddedComments(@Nullable final PsiComment comment) {
     final RegExpLanguageHost host = findRegExpHost(comment);
     return host != null && host.supportsPerl5EmbeddedComments();
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java b/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
index a5ca76041b6c..8ef91734fe0c 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
@@ -270,7 +270,7 @@ public final class RegExpAnnotator extends RegExpElementVisitor implements Annot
     final AnnotationSession session = myHolder.getCurrentAnnotationSession();
     final Map<String, RegExpGroup> namedGroups = NAMED_GROUP_MAP.get(session, new HashMap<>());
     if (namedGroups.isEmpty()) session.putUserData(NAMED_GROUP_MAP, namedGroups);
-    if (namedGroups.put(name, group) != null) {
+    if (namedGroups.put(name, group) != null && !myLanguageHosts.isDuplicateGroupNamesAllowed(group)) {
       final ASTNode node = group.getNode().findChildByType(RegExpTT.NAME);
       if (node != null) myHolder.newAnnotation(HighlightSeverity.ERROR,
                                                RegExpBundle.message("error.group.with.name.0.already.defined", name)).range(node).create();