diff --git a/editor/action_map_editor.cpp b/editor/action_map_editor.cpp
index eabe0a95e211..96d9ab1064a6 100644
--- a/editor/action_map_editor.cpp
+++ b/editor/action_map_editor.cpp
@@ -760,12 +760,26 @@ void ActionMapEditor::_add_action_pressed() {
 	_add_action(add_edit->get_text());
 }
 
+bool ActionMapEditor::_has_action(const String &p_name) const {
+	for (const ActionInfo &action_info : actions_cache) {
+		if (p_name == action_info.name) {
+			return true;
+		}
+	}
+	return false;
+}
+
 void ActionMapEditor::_add_action(const String &p_name) {
 	if (p_name.is_empty() || !_is_action_name_valid(p_name)) {
 		show_message(TTR("Invalid action name. It cannot be empty nor contain '/', ':', '=', '\\' or '\"'"));
 		return;
 	}
 
+	if (_has_action(p_name)) {
+		show_message(vformat(TTR("An action with the name '%s' already exists."), p_name));
+		return;
+	}
+
 	add_edit->clear();
 	emit_signal(SNAME("action_added"), p_name);
 }
@@ -791,6 +805,12 @@ void ActionMapEditor::_action_edited() {
 			return;
 		}
 
+		if (_has_action(new_name)) {
+			ti->set_text(0, old_name);
+			show_message(vformat(TTR("An action with the name '%s' already exists."), new_name));
+			return;
+		}
+
 		emit_signal(SNAME("action_renamed"), old_name, new_name);
 	} else if (action_tree->get_selected_column() == 1) {
 		// Deadzone Edited
diff --git a/editor/action_map_editor.h b/editor/action_map_editor.h
index cf2d871469d5..e61d1a334a2f 100644
--- a/editor/action_map_editor.h
+++ b/editor/action_map_editor.h
@@ -168,6 +168,7 @@ private:
 	void _event_config_confirmed();
 
 	void _add_action_pressed();
+	bool _has_action(const String &p_name) const;
 	void _add_action(const String &p_name);
 	void _action_edited();
 
diff --git a/editor/project_settings_editor.cpp b/editor/project_settings_editor.cpp
index b710eb2546dd..1bf6243bcc1a 100644
--- a/editor/project_settings_editor.cpp
+++ b/editor/project_settings_editor.cpp
@@ -275,10 +275,8 @@ void ProjectSettingsEditor::_editor_restart_close() {
 void ProjectSettingsEditor::_action_added(const String &p_name) {
 	String name = "input/" + p_name;
 
-	if (ProjectSettings::get_singleton()->has_setting(name)) {
-		action_map->show_message(vformat(TTR("An action with the name '%s' already exists."), name));
-		return;
-	}
+	ERR_FAIL_COND_MSG(ProjectSettings::get_singleton()->has_setting(name),
+			"An action with this name already exists.");
 
 	Dictionary action;
 	action["events"] = Array();
@@ -351,10 +349,8 @@ void ProjectSettingsEditor::_action_renamed(const String &p_old_name, const Stri
 	const String old_property_name = "input/" + p_old_name;
 	const String new_property_name = "input/" + p_new_name;
 
-	if (ProjectSettings::get_singleton()->has_setting(new_property_name)) {
-		action_map->show_message(vformat(TTR("An action with the name '%s' already exists."), new_property_name));
-		return;
-	}
+	ERR_FAIL_COND_MSG(ProjectSettings::get_singleton()->has_setting(new_property_name),
+			"An action with this name already exists.");
 
 	int order = ProjectSettings::get_singleton()->get_order(old_property_name);
 	Dictionary action = ProjectSettings::get_singleton()->get(old_property_name);