diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 08da27ac..ea1f85c7 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1263,8 +1263,6 @@ Prolog:
   type: programming
   color: "#74283c"
   primary_extension: .prolog
-  extensions:
-  - .pro
 
 Protocol Buffer:
   type: markup