diff --git a/configure.ac b/configure.ac
index fe127a4778..f66336cac1 100755
--- a/configure.ac
+++ b/configure.ac
@@ -644,7 +644,7 @@ AC_FUNC_STRFTIME
 dnl Avoid AC_FUNC_STRNLEN because it pulls in AC_SYSTEM_EXTENSIONS which
 dnl can lead to strange side effects.  So we just check for strnlen
 dnl directly, see below.
-dnlAC_FUNC_STRNLENdnl
+dnl AC_FUNC_STRNLENdnl
 AC_FUNC_VPRINTF
 
 dnl -------------------------------