diff --git a/src/secp256k1/configure.ac b/src/secp256k1/configure.ac
--- a/src/secp256k1/configure.ac
+++ b/src/secp256k1/configure.ac
@@ -224,7 +224,7 @@
   AC_RUN_IFELSE(
     [AC_LANG_PROGRAM([], [])],
     [working_native_cc=yes],
-    [working_native_cc=no],[dnl])
+    [working_native_cc=no],[:])
 
   CFLAGS_FOR_BUILD="$CFLAGS"