diff --git a/action.yml b/action.yml
index 4f5b91f..4c59052 100644
--- a/action.yml
+++ b/action.yml
@@ -9,7 +9,7 @@ runs:
   using: "composite"
   steps:
     - run: |
-        curl -OL https://github.com/casadi/mockups/releases/download/v83/mockups_${{ inputs.tag }}_Release.zip
+        curl -OL https://github.com/casadi/mockups/releases/download/v84/mockups_${{ inputs.tag }}_Release.zip
         unzip mockups_${{ inputs.tag }}_Release.zip -d mockups
         ls mockups
         ls mockups/cmake
diff --git a/matlab/include/matrix.h b/matlab/include/matrix.h
index ca6dda7..fa2e85c 100644
--- a/matlab/include/matrix.h
+++ b/matlab/include/matrix.h
@@ -50,7 +50,7 @@ typedef enum {
 } mxClassID;
 
 typedef bool mxLogical;
-typedef char16_t mxChar;
+typedef uint16_t mxChar;
 
 #include <matrix_versions.h>