diff --git a/nova_git_stats.gemspec b/nova_git_stats.gemspec
index 854b739e2..0d989d1d2 100644
--- a/nova_git_stats.gemspec
+++ b/nova_git_stats.gemspec
@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency('actionview', '>= 5.2', '< 8.0')
   s.add_dependency('activesupport', '>= 5.2', '< 8.0')
-  s.add_dependency('haml', '~> 5.0')
+  s.add_dependency('haml', '>= 5', '< 7')
   s.add_dependency('i18n', '~> 1.8')
   s.add_dependency('lazy_high_charts', '~> 1.6')
   s.add_dependency('thor', '~> 1.0')