diff --git a/src/beautifiers/phpcbf.coffee b/src/beautifiers/phpcbf.coffee
index d811ec8..0d817f7 100644
--- a/src/beautifiers/phpcbf.coffee
+++ b/src/beautifiers/phpcbf.coffee
@@ -50,7 +50,7 @@ module.exports = class PHPCBF extends Beautifier
             phpcbfPath unless isExec
             "--no-patch" unless options.phpcbf_version is 3
             "--standard=#{options.standard}" if options.standard
-            tempFile = @tempFile("temp", text)
+            tempFile = @tempFile("temp", text, ".php")
             ], {
               ignoreReturnCode: true
               help: {