diff --git a/Gemfile.lock b/Gemfile.lock
index 72791ec3..f42dd673 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,6 +3,7 @@ PATH
   specs:
     cocina-models (0.99.1)
       activesupport
+      commonmarker (= 2.0.1)
       deprecation
       dry-struct (~> 1.0)
       dry-types (~> 1.1)
@@ -37,7 +38,7 @@ GEM
     attr_extras (7.1.0)
     base64 (0.2.0)
     benchmark (0.4.0)
-    bigdecimal (3.1.8)
+    bigdecimal (3.1.9)
     byebug (11.1.3)
     committee (5.0.0)
       json_schema (~> 0.14, >= 0.14.3)
@@ -89,7 +90,7 @@ GEM
     mini_portile2 (2.8.8)
     minitest (5.25.4)
     multi_json (1.15.0)
-    nokogiri (1.17.2)
+    nokogiri (1.18.1)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     openapi3_parser (0.10.0)
@@ -106,8 +107,8 @@ GEM
     rack (3.1.8)
     rainbow (3.1.1)
     rake (13.2.1)
-    rb_sys (0.9.104)
-    regexp_parser (2.9.3)
+    rb_sys (0.9.105)
+    regexp_parser (2.10.0)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
@@ -163,7 +164,7 @@ GEM
     thor (1.3.2)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (3.1.2)
+    unicode-display_width (3.1.3)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
     uri (1.0.2)
diff --git a/cocina-models.gemspec b/cocina-models.gemspec
index 5ba96501..229250ff 100644
--- a/cocina-models.gemspec
+++ b/cocina-models.gemspec
@@ -25,6 +25,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 3.0'
 
   spec.add_dependency 'activesupport'
+  spec.add_dependency 'commonmarker', '2.0.1' # There is a breaking change in 2.0.2 with openapi3_parser
   spec.add_dependency 'deprecation'
   spec.add_dependency 'dry-struct', '~> 1.0'
   spec.add_dependency 'dry-types', '~> 1.1'