diff --git a/fenics_ice/config.py b/fenics_ice/config.py
index e37ba09..7f42fc1 100644
--- a/fenics_ice/config.py
+++ b/fenics_ice/config.py
@@ -266,6 +266,8 @@ class ErrorPropCfg(ConfigPrinter):
     """
     qoi: str = 'vaf'
     qoi_apply_vaf_mask: bool = False
+    qoi_vaf_mask_usecode: bool = False
+    qoi_vaf_mask_code: int = 1
     phase_name: str = 'error_prop'
     phase_suffix: str = ''
 
diff --git a/fenics_ice/solver.py b/fenics_ice/solver.py
index 50136ce..9c9b77e 100644
--- a/fenics_ice/solver.py
+++ b/fenics_ice/solver.py
@@ -1458,10 +1458,14 @@ def comp_Q_vaf(self, verbose=False):
         HAF = ufl.Max(b_ex * (H + (rhow/rhoi)*bed) + (1-b_ex)*(H), 0.0)
    
         if self.params.error_prop.qoi_apply_vaf_mask:
-         msk_ex = conditional(self.vaf_mask > 0.0, 1.0, 0.0)
-         Q_vaf = msk_ex * HAF * dx
+            if self.params.error_prop.qoi_vaf_mask_usecode:
+                code = float(self.params.error_prop.qoi_vaf_mask_code)
+                msk_ex = conditional(abs(self.vaf_mask-code)<1.e-10, 1.0, 0.0)
+            else:
+                msk_ex = conditional(self.vaf_mask > 0.0, 1.0, 0.0)
+            Q_vaf = msk_ex * HAF * dx
         else:
-         Q_vaf = HAF * dx
+            Q_vaf = HAF * dx
 
         if verbose:
             info(f"Q_vaf: {assemble(Q_vaf)}")