diff --git a/Gemfile.lock b/Gemfile.lock
index c4abce0..525094d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,7 +4,7 @@ PATH
     flat_api (1.0.0)
       faraday (>= 1.0.1, < 3.0)
       faraday-multipart (~> 1.0)
-      marcel (~> 1.0)
+      marcel (>= 1, < 3)
 
 GEM
   remote: https://rubygems.org/
@@ -19,7 +19,7 @@ GEM
       net-http (~> 0.5)
     json (3.0.2)
     logger (1.7.0)
-    marcel (1.2.1)
+    marcel (2.1.0)
     multipart-post (2.4.1)
     net-http (0.9.1)
       uri (>= 0.11.1)
diff --git a/flat_api.gemspec b/flat_api.gemspec
index bff4952..f66e75b 100644
--- a/flat_api.gemspec
+++ b/flat_api.gemspec
@@ -38,7 +38,7 @@ Gem::Specification.new do |s|
   # flat_api` followed by `require 'flat_api'` raised LoadError on faraday.
   s.add_runtime_dependency 'faraday', '>= 1.0.1', '< 3.0'
   s.add_runtime_dependency 'faraday-multipart', '~> 1.0'
-  s.add_runtime_dependency 'marcel', '~> 1.0'
+  s.add_runtime_dependency 'marcel', '>= 1', '< 3'
 
 
   # LICENSE has to be in the gem, not only in the repository: the gem declares Apache-2.0 above and