bug fix

1 files changed, 2 insertions, 1 deletions

diff --git a/source/slang/lower.cpp b/source/slang/lower.cpp
index bdd041f71..7f18659ae 100644
--- a/source/slang/lower.cpp
+++ b/source/slang/lower.cpp
@@ -2572,7 +2572,8 @@ struct LoweringVisitor
         else if (auto thisSubst = dynamic_cast<ThisTypeSubstitution*>(inSubstitutions))
         {
             RefPtr<ThisTypeSubstitution> result = new ThisTypeSubstitution();
-            result->sourceType = translateVal(result->sourceType);
+            if (result->sourceType)
+                result->sourceType = translateVal(result->sourceType);
             return result;
         }
         return nullptr;