diff --git a/scripts/build.sh b/scripts/build.sh
index 5e24244d7..47f8a042b 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -84,6 +84,7 @@ function convertPathOnCygwin() {
     esac
 }
 
+validatePreconditions
 enterPackerSourceDir
 ensureOutputStructure
 cleanOutputDirs