diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -2859,10 +2859,10 @@
 
               // Assignment to/from polymorphic entities are done with the
               // runtime.
-              if (lhsType->IsPolymorphic() ||
-                  lhsType->IsUnlimitedPolymorphic() ||
-                  rhsType->IsPolymorphic() ||
-                  rhsType->IsUnlimitedPolymorphic()) {
+              if (rhsType && (lhsType->IsPolymorphic() ||
+                              lhsType->IsUnlimitedPolymorphic() ||
+                              rhsType->IsPolymorphic() ||
+                              rhsType->IsUnlimitedPolymorphic())) {
                 mlir::Value lhs;
                 if (Fortran::lower::isWholeAllocatable(assign.lhs))
                   lhs = genExprMutableBox(loc, assign.lhs).getAddr();