diff --git a/layers/+lang/ruby/config.el b/layers/+lang/ruby/config.el
index a998cd86b..a4ec3d99c 100644
--- a/layers/+lang/ruby/config.el
+++ b/layers/+lang/ruby/config.el
@@ -29,4 +29,4 @@
 
 ;; Command prefixes
 
-(spacemacs/declare-prefix-for-mode mode "mt" "ruby/test")
+(spacemacs/declare-prefix-for-mode 'ruby-mode "mt" "ruby/test")