1 files changed, 10 insertions, 0 deletions
diff --git a/source/slang/slang-ast-builder.cpp b/source/slang/slang-ast-builder.cpp
index f7304f308..be71fc334 100644
--- a/source/slang/slang-ast-builder.cpp
+++ b/source/slang/slang-ast-builder.cpp
@@ -936,6 +936,11 @@ top:
     {
         return bIsSubtypeOfCWitness;
     }
+    else if (auto declAIsSubtypeOfBWitness = as<DeclaredSubtypeWitness>(aIsSubtypeOfBWitness))
+    {
+        if (declAIsSubtypeOfBWitness->isEquality())
+            return bIsSubtypeOfCWitness;
+    }
 
     // Similarly, if `b == c`, then the `a <: b` witness is a witness for `a <: c`
     //
@@ -943,6 +948,11 @@ top:
     {
         return aIsSubtypeOfBWitness;
     }
+    else if (auto declBIsSubtypeOfCWitness = as<DeclaredSubtypeWitness>(bIsSubtypeOfCWitness))
+    {
+        if (declBIsSubtypeOfCWitness->isEquality())
+            return declBIsSubtypeOfCWitness;
+    }
 
     // HACK: There is downstream code generation logic that assumes that
     // a `TransitiveSubtypeWitness` will never have a transitive witness