diff --git a/lib/google/api_client/service/simple_file_store.rb b/lib/google/api_client/service/simple_file_store.rb
index c9f510d5c..216b3fac5 100644
--- a/lib/google/api_client/service/simple_file_store.rb
+++ b/lib/google/api_client/service/simple_file_store.rb
@@ -124,7 +124,7 @@ module Google
         # Read the entire cache file from disk.
         # Will avoid reading if there have been no changes.
         def read_file
-          if !File.exists? @file_path
+          if !File.exist? @file_path
             @cache = nil
           else
             # Check for changes after our last read or write.