diff --git a/hack/lib/util.sh b/hack/lib/util.sh
index 4364dffc1d7..116e9aab36e 100644
--- a/hack/lib/util.sh
+++ b/hack/lib/util.sh
@@ -24,7 +24,13 @@ kube::util::wait_for_url() {
   local wait=${3:-0.2}
   local times=${4:-10}
 
+  which curl >/dev/null || {
+    kube::log::usage "curl must be installed"
+    exit 1
+  }
+
   local i
+
   for i in $(seq 1 $times); do
     local out
     if out=$(curl -fs $url 2>/dev/null); then