diff --git a/ruby-prof.gemspec b/ruby-prof.gemspec
index d383b981..4ee0dcfb 100644
--- a/ruby-prof.gemspec
+++ b/ruby-prof.gemspec
@@ -55,5 +55,6 @@ EOF
   spec.required_ruby_version = '>= 1.8.7'
   spec.date = DateTime.now
   spec.homepage = 'https://github.com/rdp/ruby-prof'
-  spec.add_development_dependency 'minitest', 'rake-compiler'
+  spec.add_development_dependency('minitest')
+  spec.add_development_dependency('rake-compiler')
 end
\ No newline at end of file