diff --git a/Library/Homebrew/extend/ENV.rb b/Library/Homebrew/extend/ENV.rb
index 4eeba6b982..898da62376 100644
--- a/Library/Homebrew/extend/ENV.rb
+++ b/Library/Homebrew/extend/ENV.rb
@@ -432,7 +432,7 @@ Please take one of the following actions:
   def make_jobs
     # '-j' requires a positive integral argument
     if self['HOMEBREW_MAKE_JOBS'].to_i > 0
-      self['HOMEBREW_MAKE_JOBS']
+      self['HOMEBREW_MAKE_JOBS'].to_i
     else
       Hardware.processor_count
     end