diff --git a/build.sh b/build.sh
index a396b06..4ef6296 100755
--- a/build.sh
+++ b/build.sh
@@ -220,6 +220,11 @@ if [[ -n "${APT_PROXY}" ]] && ! curl --silent "${APT_PROXY}" >/dev/null ; then
 	exit 1
 fi
 
+if [[ ${#WPA_PASSWORD} -lt 8 || ${#WPA_PASSWORD} -gt 63  ]] ; then
+	echo "WPA_PASSWORD" must be between 8 and 63 characters
+	exit 1
+fi
+
 mkdir -p "${WORK_DIR}"
 log "Begin ${BASE_DIR}"