diff --git a/panda/src/event/pythonTask.cxx b/panda/src/event/pythonTask.cxx
index 2e2213eacc..d9ea12b2f2 100644
--- a/panda/src/event/pythonTask.cxx
+++ b/panda/src/event/pythonTask.cxx
@@ -364,7 +364,7 @@ __getattribute__(PyObject *self, PyObject *attr) const {
   // We consult the instance dict first, since the user may have overridden a
   // method or something.
   PyObject *item;
-  if (PyDict_GetItemRef(__dict__, attr, &item) > 0) {
+  if (PyDict_GetItemRef(__dict__, attr, &item) != 0) {
     return item;
   }
 
diff --git a/panda/src/pgraph/nodePath_ext.cxx b/panda/src/pgraph/nodePath_ext.cxx
index 060a96e44d..af3be290b7 100644
--- a/panda/src/pgraph/nodePath_ext.cxx
+++ b/panda/src/pgraph/nodePath_ext.cxx
@@ -56,10 +56,9 @@ PyObject *Extension<NodePath>::
 __deepcopy__(PyObject *self, PyObject *memo) const {
   extern struct Dtool_PyTypedObject Dtool_NodePath;
 
-  // Borrowed reference.
   PyObject *dupe;
-  if (PyDict_GetItemRef(memo, self, &dupe) > 0) {
-    // Already in the memo dictionary.
+  if (PyDict_GetItemRef(memo, self, &dupe) != 0) {
+    // Already in the memo dictionary (or an error happened).
     return dupe;
   }
 
diff --git a/panda/src/pgraph/pandaNode_ext.cxx b/panda/src/pgraph/pandaNode_ext.cxx
index f1d25ed08e..34fc727832 100644
--- a/panda/src/pgraph/pandaNode_ext.cxx
+++ b/panda/src/pgraph/pandaNode_ext.cxx
@@ -46,10 +46,9 @@ PyObject *Extension<PandaNode>::
 __deepcopy__(PyObject *self, PyObject *memo) const {
   extern struct Dtool_PyTypedObject Dtool_PandaNode;
 
-  // Borrowed reference.
   PyObject *dupe;
-  if (PyDict_GetItemRef(memo, self, &dupe) > 0) {
-    // Already in the memo dictionary.
+  if (PyDict_GetItemRef(memo, self, &dupe) != 0) {
+    // Already in the memo dictionary (or an error happened).
     return dupe;
   }