diff --git a/Gemfile b/Gemfile
index ffde0aa..722dc6d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,7 @@ gem "nokogiri"
 gem "oga"
 gem "opal", "~> 1.8"
 gem "ox"
-gem "plurimath", "~> 0.11.3"
+gem "plurimath"
 gem "pry"
 gem "rake"
 gem "rspec"
diff --git a/unitsml.gemspec b/unitsml.gemspec
index 5fe9c12..cee61b4 100644
--- a/unitsml.gemspec
+++ b/unitsml.gemspec
@@ -34,7 +34,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "htmlentities"
   spec.add_dependency "lutaml-model", "~> 0.8.0"
-  spec.add_dependency "mml", "~> 2.3.6"
+  spec.add_dependency "mml", "~> 2.4.0"
   spec.add_dependency "ox"
   spec.add_dependency "parslet"
   spec.add_dependency "unitsdb", "~> 2.2.4"