diff --git a/build b/build
index da3efdca3c06..debf29cf437f 100755
--- a/build
+++ b/build
@@ -7,7 +7,7 @@ MYCFG=myocamlbuild_config.ml
 export CAML_LD_LIBRARY_PATH=`pwd`/_build/kernel/byterun
 
 check_config() {
- [ -f $MYCFG ] || (echo "please run ./configure first"; exit 1)
+ if [ ! -f $MYCFG ]; then echo "please run ./configure first"; exit 1; fi
 }
 
 ocb() { $OCAMLBUILD $FLAGS $*; }