diff --git a/lib/mollie/client.rb b/lib/mollie/client.rb
index 42c6710..f61f8c3 100644
--- a/lib/mollie/client.rb
+++ b/lib/mollie/client.rb
@@ -25,7 +25,10 @@ def self.configure
 
     # @return [Mollie::Client]
     def self.instance
-      Thread.current['MOLLIE_CLIENT'] ||= new(configuration.api_key)
+      Thread.current['MOLLIE_CLIENT'] ||= begin
+        self.configuration ||= Configuration.new
+        new(configuration.api_key)
+      end
     end
 
     def self.with_api_key(api_key)
diff --git a/lib/mollie/version.rb b/lib/mollie/version.rb
index 79b5c04..1366a1d 100644
--- a/lib/mollie/version.rb
+++ b/lib/mollie/version.rb
@@ -1,3 +1,3 @@
 module Mollie
-  VERSION = "3.1.2"
+  VERSION = "3.1.3"
 end