diff --git a/Library/Homebrew/extend/os/mac/keg_relocate.rb b/Library/Homebrew/extend/os/mac/keg_relocate.rb
index bb0b726493..25eae0a6cf 100644
--- a/Library/Homebrew/extend/os/mac/keg_relocate.rb
+++ b/Library/Homebrew/extend/os/mac/keg_relocate.rb
@@ -54,21 +54,20 @@ class Keg
           change_install_name(bad_name, new_name, file) unless new_name == bad_name
         end
 
-        # Count duplicate rpaths. We need to keep track of this ourselves
-        # because the MachO data is cached and this cache is not updated
-        # after modification with #delete_rpath.
-        rpath_dupe_count = Hash.new { |h, k| h[k] = -1 }
-        file.rpaths.each do |rpath|
-          rpath_dupe_count[rpath] += 1
-        end
+        # Keep track of the rpath counts for deletion of duplicates.
+        # We need to track this here since we cache the MachO data [0]
+        # and this cache is not updated after modification with #delete_rpath.
+        #
+        # [0] See os/mac/mach.rb.
+        rpath_count = Hash.new { |h, k| h[k] = file.rpaths.count(k) }
 
         each_linkage_for(file, :rpaths) do |bad_name|
-          # Strip duplicate rpaths and rpaths rooted in the build directory
+          # Strip duplicate rpaths and rpaths rooted in the build directory.
           next if !bad_name.start_with?(HOMEBREW_TEMP.to_s) &&
                   !bad_name.start_with?(HOMEBREW_TEMP.realpath.to_s) &&
-                  (rpath_dupe_count[bad_name] <= 0)
+                  (rpath_count[bad_name] == 1)
 
-          rpath_dupe_count[bad_name] -= 1
+          rpath_count[bad_name] -= 1
           delete_rpath(bad_name, file)
         end
       end