diff --git a/core/input_map.cpp b/core/input_map.cpp
index 36a0e88ae0a..ec833659f49 100644
--- a/core/input_map.cpp
+++ b/core/input_map.cpp
@@ -100,6 +100,7 @@ List<StringName> InputMap::get_actions() const {
 }
 
 List<Ref<InputEvent> >::Element *InputMap::_find_event(Action &p_action, const Ref<InputEvent> &p_event, bool *p_pressed, float *p_strength) const {
+	ERR_FAIL_COND_V(!p_event.is_valid(), NULL);
 
 	for (List<Ref<InputEvent> >::Element *E = p_action.inputs.front(); E; E = E->next()) {