diff --git a/dtool/src/interrogatedb/interrogateType.cxx b/dtool/src/interrogatedb/interrogateType.cxx
index a977ff987a..a6d6e45487 100644
--- a/dtool/src/interrogatedb/interrogateType.cxx
+++ b/dtool/src/interrogatedb/interrogateType.cxx
@@ -112,14 +112,16 @@ operator = (const InterrogateType &copy) {
 
 /**
  * Combines type with the other similar definition.  If one type is "fully
- * defined" and the other one isn't, the fully-defined type wins.
+ * defined" and the other one isn't, the fully-defined type wins.  If both
+ * types are fully defined, whichever type is marked "global" wins.
  */
 void InterrogateType::
 merge_with(const InterrogateType &other) {
   // The only thing we care about copying from the non-fully-defined type
   // right now is the global flag.
 
-  if (is_fully_defined()) {
+  if (is_fully_defined() &&
+      (!other.is_fully_defined() || (other._flags & F_global) == 0)) {
     // We win.
     _flags |= (other._flags & F_global);