diff --git a/Gopkg.toml b/Gopkg.toml
index 90b77e21222338f0025053488999d73e798d7b50..f915437c15f9a78382a62cf0809cbfd879e84b39 100644
--- a/Gopkg.toml
+++ b/Gopkg.toml
@@ -14,6 +14,10 @@
   name = "google.golang.org/grpc"
   version = "1.13.0"
 
+[[constraint]]
+  version = "=v1.6.3"
+  name = "github.com/spf13/viper"
+
 [prune]
   go-tests = true
   unused-packages = true