diff --git a/build_tools/fb_compile_mongo.sh b/build_tools/fb_compile_mongo.sh
index 38db7b5e1..c087f8161 100755
--- a/build_tools/fb_compile_mongo.sh
+++ b/build_tools/fb_compile_mongo.sh
@@ -1,5 +1,8 @@
 #!/bin/sh
 
+# fail early
+set -e
+
 if test -z $ROCKSDB_PATH; then
   ROCKSDB_PATH=~/rocksdb
 fi