diff --git a/lib/pact/mock_service/request_handlers/interactions_put.rb b/lib/pact/mock_service/request_handlers/interactions_put.rb
index b419029..c608715 100644
--- a/lib/pact/mock_service/request_handlers/interactions_put.rb
+++ b/lib/pact/mock_service/request_handlers/interactions_put.rb
@@ -23,7 +23,7 @@ def request_method
         end
 
         def respond env
-          request_body = JSON.load(env['rack.input'].string)
+          request_body = JSON.load(env['rack.input'].read)
           parsing_options = { pact_specification_version: pact_specification_version }
           interactions = request_body['interactions'].collect { | hash | Interaction.from_hash(hash, parsing_options) }
           begin
diff --git a/lib/pact/mock_service/request_handlers/pact_post.rb b/lib/pact/mock_service/request_handlers/pact_post.rb
index a370711..9dad385 100644
--- a/lib/pact/mock_service/request_handlers/pact_post.rb
+++ b/lib/pact/mock_service/request_handlers/pact_post.rb
@@ -25,7 +25,7 @@ def request_method
         end
 
         def respond env
-          body = env['rack.input'].string
+          body = env['rack.input'].read
           consumer_contract_details = body.size > 0 ? JSON.parse(body, symbolize_names: true) : {}
           consumer_contract_params = default_options.merge(consumer_contract_details.merge(interactions: verified_interactions))
           consumer_contract_writer = ConsumerContractWriter.new(consumer_contract_params, logger)