diff --git a/src/testing.c b/src/testing.c
index f01f73a..c2389bd 100644
--- a/src/testing.c
+++ b/src/testing.c
@@ -1096,7 +1096,10 @@
     void
 f_test_ignore_error(typval_T *argvars, typval_T *rettv UNUSED)
 {
-     ignore_error_for_testing(tv_get_string(&argvars[0]));
+    if (argvars[0].v_type != VAR_STRING)
+	emsg(_(e_invarg));
+    else
+	ignore_error_for_testing(tv_get_string(&argvars[0]));
 }
 
     void