diff --git a/http-2.gemspec b/http-2.gemspec
index 16078c68..269b4b67 100644
--- a/http-2.gemspec
+++ b/http-2.gemspec
@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
   spec.summary       = spec.description
   spec.homepage      = 'https://github.com/igrigorik/http-2'
   spec.license       = 'MIT'
-  spec.required_ruby_version = '>=2.0.0'
+  spec.required_ruby_version = '>=2.1.0'
 
   spec.files         = `git ls-files`.split($INPUT_RECORD_SEPARATOR)
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
diff --git a/lib/http/2/client.rb b/lib/http/2/client.rb
index f4aacfa8..95ede3fd 100644
--- a/lib/http/2/client.rb
+++ b/lib/http/2/client.rb
@@ -34,13 +34,23 @@ def initialize(**settings)
     # @see Connection
     # @param frame [Hash]
     def send(frame)
-      send_connection_preface
+      if @state == :waiting_connection_preface
+        send_connection_preface
+      end
       super(frame)
     end
 
+    def connection_management(frame)
+      if @state == :waiting_connection_preface
+        send_connection_preface
+        connection_settings(frame)
+      else
+        super(frame)
+      end
+    end
+
     # Emit the connection preface if not yet
     def send_connection_preface
-      return unless @state == :waiting_connection_preface
       @state = :connected
       emit(:frame, CONNECTION_PREFACE_MAGIC)