diff --git a/src/wallBC.cpp b/src/wallBC.cpp
index ad90531f6..798e3437a 100644
--- a/src/wallBC.cpp
+++ b/src/wallBC.cpp
@@ -207,6 +207,30 @@ 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 3caf79fe9..4f7d15117 100644
--- a/src/wallBC.hpp
+++ b/src/wallBC.hpp
@@ -78,6 +78,7 @@ class WallBC : public BoundaryCondition {
   ~WallBC();
 
   void computeBdrFlux(Vector &normal, Vector &stateIn, DenseMatrix &gradState, double radius, Vector &bdrFlux);
+  void computeBdrPrimitiveStateForGradient(const Vector &primIn, Vector &primBC) const override;
 
   virtual void initBCs();