diff --git a/tests_ispcpp/error_0.ispc b/tests_ispcpp/error_0.ispc
index 39f57d0d..46768163 100644
--- a/tests_ispcpp/error_0.ispc
+++ b/tests_ispcpp/error_0.ispc
@@ -1,6 +1,6 @@
 //@error
 //assigning mismatched polymorphic types
 
-export void foo(floating$0 bar) {
+export void foo(uniform floating$0 bar) {
     floating$1 baz = bar;
 }
diff --git a/tests_ispcpp/error_2.ispc b/tests_ispcpp/error_2.ispc
index 6f4adfe0..1be1c6ac 100644
--- a/tests_ispcpp/error_2.ispc
+++ b/tests_ispcpp/error_2.ispc
@@ -1,6 +1,6 @@
 //@error
 //assigning mismatched polymorphic types
 
-export void foo(number$0 bar) {
-    floating$0 baz = bar;
+export void foo(uniform floating$0 bar) {
+    integer baz = bar;
 }
diff --git a/type.cpp b/type.cpp
index 8450ee23..9da21a0e 100644
--- a/type.cpp
+++ b/type.cpp
@@ -855,15 +855,17 @@ PolyType::CanBeType(const Type *t) const {
 
     const AtomicType *at = CastType<AtomicType>(t);
 
-    switch (restriction) {
-        case TYPE_INTEGER:
-            return at->IsIntType();
-        case TYPE_FLOATING:
-            return at->IsFloatType();
-        case TYPE_NUMBER:
-            return at->IsIntType() || at->IsFloatType();
-        default:
-            FATAL("Unmatched case for polymorphic restriction");
+    if (at) {
+        switch (restriction) {
+            case TYPE_INTEGER:
+                return at->IsIntType();
+            case TYPE_FLOATING:
+                return at->IsFloatType();
+            case TYPE_NUMBER:
+                return at->IsIntType() || at->IsFloatType();
+            default:
+                FATAL("Unmatched case for polymorphic restriction");
+        }
     }
 
     // not an atomic type or polymorphic type