diff --git a/generated/google-apis-discovery_v1/Gemfile b/generated/google-apis-discovery_v1/Gemfile
index 6fa8bb627a6..6fa5a91c87c 100644
--- a/generated/google-apis-discovery_v1/Gemfile
+++ b/generated/google-apis-discovery_v1/Gemfile
@@ -21,3 +21,5 @@ platforms :ruby do
     gem "redcarpet", "~> 3.5"
   end
 end
+
+gem "google-apis-core", path: "../../google-apis-core"
diff --git a/google-apis-core/google-apis-core.gemspec b/google-apis-core/google-apis-core.gemspec
index 041ff3c6064..4da9119b710 100644
--- a/google-apis-core/google-apis-core.gemspec
+++ b/google-apis-core/google-apis-core.gemspec
@@ -25,6 +25,6 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency "addressable", "~> 2.5", ">= 2.5.1"
   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 "httpclient", ">= 2.8.3", "< 3.a"
+  gem.add_runtime_dependency "mutex_m" # used by httpclient
 end
diff --git a/google-apis-generator/Gemfile b/google-apis-generator/Gemfile
index db849e39e50..a300a6c4336 100644
--- a/google-apis-generator/Gemfile
+++ b/google-apis-generator/Gemfile
@@ -36,3 +36,5 @@ platforms :ruby do
     gem 'pry-byebug', '~> 3.2'
   end
 end
+
+gem "google-apis-core", path: "../google-apis-core"