diff --git a/configure.ac b/configure.ac
index 8f71ab4..ae5bd63 100644
--- a/configure.ac
+++ b/configure.ac
@@ -27,7 +27,7 @@ AC_CONFIG_HEADERS([config.h])
 # Checks for programs
 AC_USE_SYSTEM_EXTENSIONS
 AC_C_RESTRICT
-AC_PROG_CC_C99
+AC_PROG_CC
 gl_EARLY
 gl_INIT
 AC_PROG_MAKE_SET