diff --git a/configure.ac b/configure.ac
index 067d4b3..2ae99f1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -42,9 +42,7 @@ AC_ARG_WITH(encodingsdir,
 	[ENCODINGSDIR="$DEFAULT_ENCODINGSDIR"])
 AC_SUBST(ENCODINGSDIR)
 
-# zlib
-
-AC_CHECK_LIB(z, gzclose) 
+AC_CHECK_LIB(z, gzclose, , AC_MSG_ERROR([Cannot find zlib])) 
 
 # Check for dependencies
 PKG_CHECK_MODULES(FONTENC, xproto)