diff --git a/Gemfile.lock b/Gemfile.lock
index e1432db12..43f0484f4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -140,11 +140,11 @@ GEM
     composite_primary_keys (10.0.5)
       activerecord (~> 5.1.0, >= 5.1.6)
     concurrent-ruby (1.1.5)
-    coveralls (0.8.22)
+    coveralls (0.8.23)
       json (>= 1.8, < 3)
       simplecov (~> 0.16.1)
       term-ansicolor (~> 1.3)
-      thor (~> 0.19.4)
+      thor (>= 0.19.4, < 2.0)
       tins (~> 1.6)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
@@ -481,7 +481,7 @@ GEM
       tins (~> 1.0)
     test-unit (3.3.3)
       power_assert
-    thor (0.19.4)
+    thor (0.20.3)
     thread_safe (0.3.6)
     tilt (2.0.9)
     tins (1.20.2)