diff --git a/google-apis-core/google-apis-core.gemspec b/google-apis-core/google-apis-core.gemspec
index 041ff3c6064..fb5756f6945 100644
--- a/google-apis-core/google-apis-core.gemspec
+++ b/google-apis-core/google-apis-core.gemspec
@@ -26,5 +26,5 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency "mini_mime", "~> 1.0"
   gem.add_runtime_dependency "googleauth", "~> 1.9"
   gem.add_runtime_dependency "httpclient", ">= 2.8.1", "< 3.a"
-  gem.add_runtime_dependency "rexml"
+  gem.add_runtime_dependency "rexml", ">= 3.2.7", "< 4.0"
 end