1 files changed, 1 insertions, 1 deletions
diff --git a/source/slang/legalize-types.cpp b/source/slang/legalize-types.cpp
index 211685aa2..d1cef4dac 100644
--- a/source/slang/legalize-types.cpp
+++ b/source/slang/legalize-types.cpp
@@ -916,7 +916,7 @@ LegalType legalizeType(
             }
 
             legalType = builder.getResult();
-            context->mapDeclRefToLegalType.Add(declRef, legalType);
+            context->mapDeclRefToLegalType.AddIfNotExists(declRef, legalType);
             return legalType;
         }