diff --git a/pkgs/development/tools/misc/mdl/Gemfile.lock b/pkgs/development/tools/misc/mdl/Gemfile.lock
index 40fb2f51a60d..0e01c85002b4 100644
--- a/pkgs/development/tools/misc/mdl/Gemfile.lock
+++ b/pkgs/development/tools/misc/mdl/Gemfile.lock
@@ -8,7 +8,7 @@ GEM
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
-    mdl (0.12.0)
+    mdl (0.13.0)
       kramdown (~> 2.3)
       kramdown-parser-gfm (~> 1.1)
       mixlib-cli (~> 2.1, >= 2.1.1)
diff --git a/pkgs/development/tools/misc/mdl/gemset.nix b/pkgs/development/tools/misc/mdl/gemset.nix
index 1fd09e878088..7c9f7b003789 100644
--- a/pkgs/development/tools/misc/mdl/gemset.nix
+++ b/pkgs/development/tools/misc/mdl/gemset.nix
@@ -48,10 +48,10 @@
     platforms = [];
     source = {
       remotes = ["https://rubygems.org"];
-      sha256 = "1gk42gayn8d2084ak6wvdwch00wb0acvncglfdhi5n0ap93q6wb6";
+      sha256 = "1a463jx8v4a3lgmmfalq73c337d66hc21q4vnfar1qf4lhk5wyi0";
       type = "gem";
     };
-    version = "0.12.0";
+    version = "0.13.0";
   };
   mixlib-cli = {
     groups = ["default"];