diff --git a/Library/Homebrew/utils.rb b/Library/Homebrew/utils.rb
index 1f305a3b84..4bf9dbcc47 100644
--- a/Library/Homebrew/utils.rb
+++ b/Library/Homebrew/utils.rb
@@ -252,10 +252,28 @@ module GitHub extend self
   ISSUES_URI = URI.parse("https://api.github.com/search/issues")
 
   Error = Class.new(RuntimeError)
-  RateLimitExceededError = Class.new(Error)
   HTTPNotFoundError = Class.new(Error)
   AuthenticationFailedError = Class.new(Error)
 
+  class RateLimitExceededError < Error
+    def initialize(reset, error)
+      super <<-EOS.undent
+        GitHub #{error}
+        Try again in #{pretty_ratelimit_reset(reset)}, or create an API token:
+          https://github.com/settings/applications
+        and then set HOMEBREW_GITHUB_API_TOKEN.
+        EOS
+    end
+
+    def pretty_ratelimit_reset(reset)
+      if (seconds = Time.at(reset) - Time.now) > 180
+        "%d minutes %d seconds" % [seconds / 60, seconds % 60]
+      else
+        "#{seconds} seconds"
+      end
+    end
+  end
+
   def open url, headers={}, &block
     # This is a no-op if the user is opting out of using the GitHub API.
     return if ENV['HOMEBREW_NO_GITHUB_API']
@@ -282,13 +300,8 @@ module GitHub extend self
   def handle_api_error(e)
     if e.io.meta["x-ratelimit-remaining"].to_i <= 0
       reset = e.io.meta.fetch("x-ratelimit-reset").to_i
-
-      raise RateLimitExceededError, <<-EOS.undent, e.backtrace
-        GitHub #{Utils::JSON.load(e.io.read)['message']}
-        Try again in #{pretty_ratelimit_reset(reset)}, or create an API token:
-          https://github.com/settings/applications
-        and then set HOMEBREW_GITHUB_API_TOKEN.
-        EOS
+      error = Utils::JSON.load(e.io.read)["message"]
+      raise RateLimitExceededError.new(reset, error)
     end
 
     case e.io.status.first
@@ -301,14 +314,6 @@ module GitHub extend self
     end
   end
 
-  def pretty_ratelimit_reset(reset)
-    if (seconds = Time.at(reset) - Time.now) > 180
-      "%d minutes %d seconds" % [seconds / 60, seconds % 60]
-    else
-      "#{seconds} seconds"
-    end
-  end
-
   def issues_matching(query, qualifiers={})
     uri = ISSUES_URI.dup
     uri.query = build_query_string(query, qualifiers)