diff --git a/configure.ac b/configure.ac
index 9f33852..02a62b8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,6 +3,9 @@
 # FIXME - add project url as the last argument
 AC_INIT(gf-complete, 1.0)
 
+# Override default CFLAGS
+: ${CFLAGS="-Wall -Wpointer-arith -O3 -g"}
+
 AC_PREREQ([2.61])
 
 AM_INIT_AUTOMAKE([no-dependencies foreign])
@@ -16,9 +19,6 @@ AC_CONFIG_MACRO_DIR([m4])
 # This prevents './configure; make' from trying to run autotools.
 AM_MAINTAINER_MODE([disable])
 
-# Override default CFLAGS
-CFLAGS="-Wall -Wpointer-arith -O3 -g"
-
 dnl Compiling with per-target flags requires AM_PROG_CC_C_O.
 AC_PROG_CC