diff --git a/src/wallBC.cpp b/src/wallBC.cpp
index 90c605d75..d07adad1d 100644
--- a/src/wallBC.cpp
+++ b/src/wallBC.cpp
@@ -236,6 +236,30 @@ void WallBC::computeBdrFlux(Vector &normal, Vector &stateIn, DenseMatrix &gradSt
   }
 }
 
+void WallBC::computeBdrPrimitiveStateForGradient(const Vector &primIn, Vector &primBC) const {
+  primBC = primIn;
+
+  switch (wallType_) {
+    case INV:
+      // TODO(trevilo): fix
+      break;
+    case VISC_ADIAB:
+      // TODO(trevilo): fix
+      break;
+    case VISC_ISOTH:
+      // no-slip
+      for (int i = 0; i < nvel_; i++) {
+        primBC[1 + i] = 0.0;
+      }
+      // isothermal
+      primBC[nvel_ + 1] = wallTemp_;
+      break;
+    case VISC_GNRL:
+      // TODO(trevilo): fix
+      break;
+  }
+}
+
 void WallBC::integrationBC(Vector &y, const Vector &x, const elementIndexingData &elem_index_data, ParGridFunction *Up,
                            ParGridFunction *gradUp, const boundaryFaceIntegrationData &boundary_face_data,
                            const int &maxIntPoints, const int &maxDofs) {
diff --git a/src/wallBC.hpp b/src/wallBC.hpp
index a277b81aa..c6cc10d00 100644
--- a/src/wallBC.hpp
+++ b/src/wallBC.hpp
@@ -83,6 +83,7 @@ class WallBC : public BoundaryCondition {
 
   void computeBdrFlux(Vector &normal, Vector &stateIn, DenseMatrix &gradState, Vector transip, double delta,
                       double distance, Vector &bdrFlux);
+  void computeBdrPrimitiveStateForGradient(const Vector &primIn, Vector &primBC) const override;
 
   virtual void initBCs();