diff --git a/build.sh b/build.sh
index d1d3be296..a083f4946 100755
--- a/build.sh
+++ b/build.sh
@@ -33,6 +33,8 @@ fi
 # Configure all
 
 if [ "$1" = "auto" ]; then
+	echo "Invoking 'make defconfig'..."
+	make defconfig || clean_exit 2
 	echo "Building IBM PC image..."
 	cp ibmpc-1440.config .config
 else