diff --git a/lib/gitlab/ci/config/entry/validators.rb b/lib/gitlab/ci/config/entry/validators.rb
index 30c52dd65e812b323f779e113568d36e23784fb9..bd7428b1272bc414d7e776590d94e4dc2d5870a0 100644
--- a/lib/gitlab/ci/config/entry/validators.rb
+++ b/lib/gitlab/ci/config/entry/validators.rb
@@ -66,7 +66,8 @@ module Gitlab
             private
 
             def look_like_regexp?(value)
-              value.start_with?('/') && value.end_with?('/')
+              value.is_a?(String) && value.start_with?('/') &&
+                value.end_with?('/')
             end
 
             def validate_regexp(value)
@@ -92,7 +93,6 @@ module Gitlab
             end
 
             def validate_string_or_regexp(value)
-              return true if value.is_a?(Symbol)
               return false unless value.is_a?(String)
               return validate_regexp(value) if look_like_regexp?(value)
               true