diff --git a/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_hr.py b/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_hr.py
index b8540b3a04..c8a9ec58bb 100644
--- a/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_hr.py
+++ b/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_hr.py
@@ -106,6 +106,10 @@ def fix_metadata(self, cubes):
         return cubes
 
 
+class SfcWindmax(SfcWind):
+    """Fixes for sfcWindmax."""
+
+
 class Uas(SfcWind):
     """Fixes for uas."""
 
diff --git a/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_xr.py b/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_xr.py
index 644155e690..201ffcca63 100644
--- a/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_xr.py
+++ b/esmvalcore/cmor/_fixes/cmip6/mpi_esm1_2_xr.py
@@ -37,6 +37,10 @@ class SfcWind(BaseSfcWind):
     """Fixes for sfcWind."""
 
 
+class SfcWindmax(BaseSfcWind):
+    """Fixes for sfcWindmax."""
+
+
 class Uas(BaseSfcWind):
     """Fixes for uas."""