diff --git a/tool/client.cc b/tool/client.cc
index 6cd40fb..6bc8e39 100644
--- a/tool/client.cc
+++ b/tool/client.cc
@@ -107,7 +107,7 @@
     },
     {
       "-root-certs", kOptionalArgument,
-      "A filename containing one of more PEM root certificates. Implies that"
+      "A filename containing one of more PEM root certificates. Implies that "
       "verification is required.",
     },
     {