diff --git a/build-infer.sh b/build-infer.sh
index 813dd29d2..678559266 100755
--- a/build-infer.sh
+++ b/build-infer.sh
@@ -18,7 +18,9 @@ PLATFORM="$(uname)"
 SANDCASTLE=${SANDCASTLE:-}
 NCPU="$(getconf _NPROCESSORS_ONLN 2>/dev/null || echo 1)"
 INFER_OPAM_DEFAULT_SWITCH="ocaml-variants.4.07.1+flambda"
+INFER_OPAM_DEFAULT_COMPILER="$INFER_OPAM_DEFAULT_SWITCH"
 INFER_OPAM_SWITCH=${INFER_OPAM_SWITCH:-$INFER_OPAM_DEFAULT_SWITCH}
+INFER_OPAM_COMPILER=${INFER_OPAM_COMPILER:-$INFER_OPAM_DEFAULT_COMPILER}
 
 function usage() {
   echo "Usage: $0 [-y] [targets]"