diff --git a/Gemfile b/Gemfile
index 6010395..b356727 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,13 @@
-source 'https://rubygems.org'
+# frozen_string_literal: true
+
+source "https://rubygems.org"
 
 # Specify your gem's dependencies in fluent-plugin-gcs.gemspec
 gemspec
+
+gem "rake", "~> 13.0"
+gem "rr", "= 1.1.2"
+gem "test-unit", ">= 3.0.8"
+gem "test-unit-rr", ">= 1.0.3"
+gem "timecop"
+gem "solargraph"
diff --git a/fluent-plugin-gcs.gemspec b/fluent-plugin-gcs.gemspec
index b87a204..6b48663 100644
--- a/fluent-plugin-gcs.gemspec
+++ b/fluent-plugin-gcs.gemspec
@@ -22,10 +22,4 @@ Gem::Specification.new do |spec|
 
   spec.add_runtime_dependency "fluentd", [">= 0.14.22", "< 2"]
   spec.add_runtime_dependency "google-cloud-storage", "~> 1.1"
-
-  spec.add_development_dependency "rake", ">= 12.3.3"
-  spec.add_development_dependency "rr", "= 1.1.2"
-  spec.add_development_dependency "test-unit", ">= 3.0.8"
-  spec.add_development_dependency "test-unit-rr", ">= 1.0.3"
-  spec.add_development_dependency "timecop"
 end
diff --git a/lib/fluent/plugin/out_gcs.rb b/lib/fluent/plugin/out_gcs.rb
index 6a6334c..7b34099 100644
--- a/lib/fluent/plugin/out_gcs.rb
+++ b/lib/fluent/plugin/out_gcs.rb
@@ -131,7 +131,7 @@ def write(chunk)
         opts.merge!(@encryption_opts)
 
         log.debug { "out_gcs: upload chunk:#{chunk.key} to gcs://#{@bucket}/#{path} options: #{opts}" }
-        @gcs_bucket.upload_file(obj.path, path, opts)
+        @gcs_bucket.upload_file(obj.path, path, **opts)
       end
     end
 
@@ -153,7 +153,7 @@ def hex_random(chunk)
 
     def check_object_exists(path)
       if !@blind_write
-        return @gcs_bucket.find_file(path, @encryption_opts)
+        return @gcs_bucket.find_file(path, **@encryption_opts)
       else
         return false
       end