diff --git a/src/ecmascript/mujs/element.c b/src/ecmascript/mujs/element.c
index 4be9b09b3..6a399a4fc 100644
--- a/src/ecmascript/mujs/element.c
+++ b/src/ecmascript/mujs/element.c
@@ -2577,13 +2577,13 @@ mjs_element_contains(js_State *J)
 	dom_node *el = (dom_node *)(mjs_getprivate(J, 0));
 
 	if (!el) {
-		js_pushboolean(J, 0);
+		js_error(J, "error");
 		return;
 	}
 	dom_node *el2 = (dom_node *)(mjs_getprivate(J, 1));
 
 	if (!el2) {
-		js_pushboolean(J, 0);
+		js_error(J, "error");
 		return;
 	}
 #ifdef ECMASCRIPT_DEBUG
diff --git a/src/ecmascript/mujs/fragment.c b/src/ecmascript/mujs/fragment.c
index 75d87e4f3..f2a25e0f3 100644
--- a/src/ecmascript/mujs/fragment.c
+++ b/src/ecmascript/mujs/fragment.c
@@ -953,13 +953,13 @@ mjs_fragment_contains(js_State *J)
 	dom_node *el = (dom_node *)(mjs_getprivate_fragment(J, 0));
 
 	if (!el) {
-		js_pushboolean(J, 0);
+		js_error(J, "error");
 		return;
 	}
 	dom_node *el2 = (dom_node *)(mjs_getprivate_fragment(J, 1));
 
 	if (!el2) {
-		js_pushboolean(J, 0);
+		js_error(J, "error");
 		return;
 	}
 #ifdef ECMASCRIPT_DEBUG
diff --git a/src/ecmascript/mujs/text.c b/src/ecmascript/mujs/text.c
index ea24eba95..1abe09120 100644
--- a/src/ecmascript/mujs/text.c
+++ b/src/ecmascript/mujs/text.c
@@ -985,13 +985,13 @@ mjs_text_contains(js_State *J)
 	dom_node *el = (dom_node *)(mjs_getprivate_text(J, 0));
 
 	if (!el) {
-		js_pushboolean(J, 0);
+		js_error(J, "error");
 		return;
 	}
 	dom_node *el2 = (dom_node *)(mjs_getprivate_text(J, 1));
 
 	if (!el2) {
-		js_pushboolean(J, 0);
+		js_error(J, "error");
 		return;
 	}
 #ifdef ECMASCRIPT_DEBUG