diff --git a/aegisub/configure.in b/aegisub/configure.in
index f9b6e2368..0813d018a 100644
--- a/aegisub/configure.in
+++ b/aegisub/configure.in
@@ -480,7 +480,11 @@ if test "$agi_cv_with_iconv" = "yes"; then
   AC_AGI_COMPILE([iconv (const)], [iconv_const], [$ICONV_CFLAGS], [$ICONV_LDFLAGS],[
 #include <iconv.h>
 int main(void) {
-  size_t iconv (iconv_t cd, const char** in, size_t *inbytesleft, char** out, size_t *outbytesleft);
+  iconv_t cd = iconv_open("UTF-16", "UTF-8");
+  const char *in = "in";
+  char *out = new char();
+  size_t res, inbytesleft, outbytesleft;
+  res = iconv(cd, &in, &inbytesleft, &out, &outbytesleft);
   return 0;
 } ])