diff --git a/ext/iconv/config.m4 b/ext/iconv/config.m4
index d5ef64022ac36..ac57c81e7d472 100644
--- a/ext/iconv/config.m4
+++ b/ext/iconv/config.m4
@@ -92,7 +92,7 @@ int main() {
 
 int main() {
   iconv_t cd;
-  cd = iconv_open( "*blahblah*", "*blahblah*" );
+  cd = iconv_open( "*blahblah*", "*blahblahblah*" );
   if (cd == (iconv_t)(-1)) {
     if (errno == EINVAL) {
       return 0;