diff --git a/csmith/csmith_gen.sh b/csmith/csmith_gen.sh
index 60ad876..1e2517b 100755
--- a/csmith/csmith_gen.sh
+++ b/csmith/csmith_gen.sh
@@ -1,6 +1,12 @@
 #!/bin/bash
 
-USAGE="$0 output_dir nb_tests"
+USAGE="$0 output_dir nb_tests
+You may also set COMPILE_CMD to eg. 'gcc -O2' if you want to override the
+default command."
+
+if [ -z "$COMPILE_CMD" ] ; then
+    COMPILE_CMD='gcc -O2'
+fi
 
 if [ "$#" -lt 2 ] ; then
     >&2 echo -e "Missing argument(s). Usage:\n$USAGE"
@@ -28,7 +34,7 @@ for _num in $(seq 1 $NB_TESTS); do
     csmith > "$path.c"
     sed -i 's/^static \(.* func_\)/\1/g' "$path.c"
     echo -ne "\r>>> $num.bin          "
-    gcc -O2 -I/usr/include/csmith-2.3.0/ -w "$path.c" -o "$path.orig.bin"
+    $COMPILE_CMD -I/usr/include/csmith-2.3.0/ -w "$path.c" -o "$path.orig.bin"
     objcopy --remove-section '.eh_frame' --remove-section '.eh_frame_hdr' \
         "$path.orig.bin" "$path.bin"
     echo -ne "\r>>> $num.eh.bin          "