diff --git a/backend/spree_backend.gemspec b/backend/spree_backend.gemspec
index 6325d36845c..2945eec4239 100644
--- a/backend/spree_backend.gemspec
+++ b/backend/spree_backend.gemspec
@@ -29,7 +29,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'spree_core', ">= #{s.version}"
 
   s.add_dependency 'babel-transpiler', '~> 0.7'
-  s.add_dependency 'bootstrap',       '~> 4.0'
+  s.add_dependency 'bootstrap',       '>= 4', '< 6'
   s.add_dependency 'glyphicons',      '~> 1.0'
   s.add_dependency 'flatpickr',       '~> 4.6'
   s.add_dependency 'inline_svg',      '~> 1.5'