diff --git a/Source/Modules/csharp.cxx b/Source/Modules/csharp.cxx
index 24bc48f0a..6b0ad6edc 100644
--- a/Source/Modules/csharp.cxx
+++ b/Source/Modules/csharp.cxx
@@ -361,8 +361,10 @@ public:
     }
 
     // module class and intermediary classes are always created
-    addSymbol(imclass_name, n);
-    addSymbol(module_class_name, n);
+    if (!addSymbol(imclass_name, n))
+      return SWIG_ERROR;
+    if (!addSymbol(module_class_name, n))
+      return SWIG_ERROR;
 
     imclass_class_code = NewString("");
     proxy_class_def = NewString("");
diff --git a/Source/Modules/java.cxx b/Source/Modules/java.cxx
index 591ed2e84..bfa02d7e2 100644
--- a/Source/Modules/java.cxx
+++ b/Source/Modules/java.cxx
@@ -374,8 +374,10 @@ public:
     constants_interface_name = NewStringf("%sConstants", module_class_name);
 
     // module class and intermediary classes are always created
-    addSymbol(imclass_name, n);
-    addSymbol(module_class_name, n);
+    if (!addSymbol(imclass_name, n))
+      return SWIG_ERROR;
+    if (!addSymbol(module_class_name, n))
+      return SWIG_ERROR;
 
     imclass_class_code = NewString("");
     proxy_class_def = NewString("");