Don't optimize when debug is enabled
diff --git a/acinclude.m4 b/acinclude.m4
index f450f9a..e12fd01 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -61,6 +61,6 @@
 	fi
 
 	if (test "${debug_enable}" = "yes" && test "${ac_cv_prog_cc_g}" = "yes"); then
-		CFLAGS="$CFLAGS -g"
+		CFLAGS="$CFLAGS -g -O0"
 	fi
 ])