diff --git a/Gemfile.lock b/Gemfile.lock
index 2e7e855cf..3d44b7baa 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -435,7 +435,7 @@ GEM
     pg (1.1.4)
     pghero (2.3.0)
       activerecord (>= 5)
-    pkg-config (1.3.8)
+    pkg-config (1.3.9)
     premailer (1.11.1)
       addressable
       css_parser (>= 1.6.0)