diff --git a/src/libsysprof-capture/sysprof-capture-condition.c b/src/libsysprof-capture/sysprof-capture-condition.c
index 8f891577..4b829a98 100644
--- a/src/libsysprof-capture/sysprof-capture-condition.c
+++ b/src/libsysprof-capture/sysprof-capture-condition.c
@@ -269,6 +269,7 @@ sysprof_capture_condition_copy (const SysprofCaptureCondition *self)
     }
 
   sysprof_assert_not_reached ();
+  return NULL;
 }
 
 static void