diff --git a/committee.gemspec b/committee.gemspec
index 1e39a078..ebdaaad2 100644
--- a/committee.gemspec
+++ b/committee.gemspec
@@ -22,11 +22,11 @@ Gem::Specification.new do |s|
 
   s.add_dependency "json_schema", "~> 0.14", ">= 0.14.3"
 
-  s.add_dependency "rack", ">= 1.5"
+  s.add_dependency "rack", ">= 1.5", "< 3.1"
   s.add_dependency "openapi_parser", "~> 2.0"
 
   s.add_development_dependency "minitest", "~> 5.3"
-  s.add_development_dependency "rack-test", "~> 0.8"
+  s.add_development_dependency "rack-test"
   s.add_development_dependency "rake", "~> 13.1"
   s.add_development_dependency "pry"
   s.add_development_dependency "pry-byebug"
diff --git a/lib/committee/request_unpacker.rb b/lib/committee/request_unpacker.rb
index abddd264..c6293db1 100644
--- a/lib/committee/request_unpacker.rb
+++ b/lib/committee/request_unpacker.rb
@@ -46,7 +46,11 @@ def unpack_request_params(request)
       if @allow_form_params && %w[application/x-www-form-urlencoded multipart/form-data].include?(request.media_type)
         # Actually, POST means anything in the request body, could be from
         # PUT or PATCH too. Silly Rack.
-        return [request.POST, true] if request.POST
+        begin
+          return [request.POST, true] if request.POST
+        ensure
+          request.body.rewind
+        end
       end
 
       [{}, false]