diff --git a/simpegEM/TDEM/TDEM_b.py b/simpegEM/TDEM/TDEM_b.py
index 2eada637..35aaf5c9 100644
--- a/simpegEM/TDEM/TDEM_b.py
+++ b/simpegEM/TDEM/TDEM_b.py
@@ -76,8 +76,24 @@ class ProblemTDEM_b(ProblemBaseTDEM):
             return {'b':b, 'e':e}
 
         self.makeMassMatrices(m)
-        Y = self.forward(m, AhRHS, AhCalcFields)
-        return Y
+        return self.forward(m, AhRHS, AhCalcFields)
+
+    def solveAht(self, m, p):
+        
+        def AhtRHS(tInd, u):
+            rhs = self.MfMui*self.mesh.edgeCurl*self.MeSigmaI*p.get_e(tInd) + p.get_b(tInd)
+            if tInd == self.nTimes-1:
+                return rhs
+            dt = self.getDt(tInd+1)
+            return rhs + 1./dt*self.MfMui*u.get_b(tInd+1)
+        
+        def AhtCalcFields(sol, solType, tInd):
+            b = sol
+            e = self.MeSigmaI*self.mesh.edgeCurl.T*self.MfMui*b - self.MeSigmaI*p.get_e(tInd)
+            return {'b':b, 'e':e}
+
+        self.makeMassMatrices(m)
+        return self.adjoint(m, AhtRHS, AhtCalcFields)
 
     ####################################################
     # Functions for tests
diff --git a/simpegEM/Tests/test_forward_EMproblem.py b/simpegEM/Tests/test_forward_EMproblem.py
index 42ad57dd..95dcb72f 100644
--- a/simpegEM/Tests/test_forward_EMproblem.py
+++ b/simpegEM/Tests/test_forward_EMproblem.py
@@ -248,7 +248,7 @@ class TDEM_bDerivTests(unittest.TestCase):
         V1 = d.T.dot(dat.projectFields(f))
         V2 = f.fieldVec().dot(dat.projectFieldsAdjoint(d).fieldVec())
 
-        self.assertTrue((V1-V2)/V1<1e-12)
+        self.assertLess((V1-V2)/np.abs(V1), 1e-8)
 
     def test_adjointAhVsAht(self):
         prb = self.prb
@@ -267,7 +267,45 @@ class TDEM_bDerivTests(unittest.TestCase):
 
         V1 = f2.fieldVec().dot(prb.AhVec(sigma, f1).fieldVec())
         V2 = f1.fieldVec().dot(prb.AhtVec(sigma, f2).fieldVec())
-        self.assertLess(np.abs(V1-V2)/V1, 1e-12)
+        self.assertLess(np.abs(V1-V2)/np.abs(V1), 1e-8)
+
+    def test_solveAhtVsAhtVec(self):
+        prb = self.prb
+        mesh = self.mesh
+        sigma = np.random.rand(mesh.nCz)
+
+        f1 = EM.TDEM.FieldsTDEM(mesh, 1, prb.nTimes, 'b')
+        for i in range(f1.nTimes):
+            f1.set_b(np.random.rand(mesh.nF, 1), i)
+            f1.set_e(np.random.rand(mesh.nE, 1), i)
+
+        f2 = prb.solveAht(sigma, f1)
+        f3 = prb.AhtVec(sigma, f2)
+
+        V1 = np.linalg.norm(f3.fieldVec()-f1.fieldVec())
+        V2 = np.linalg.norm(f1.fieldVec())
+        self.assertLess(V1/V2, 1e-8)
+
+    def test_adjointsolveAhVssolveAht(self):
+        prb = self.prb
+        mesh = self.mesh
+        sigma = self.sigma
+
+        f1 = EM.TDEM.FieldsTDEM(prb.mesh, 1, prb.nTimes, 'b')
+        for i in range(f1.nTimes):
+            f1.set_b(np.random.rand(mesh.nF, 1), i)
+            f1.set_e(np.random.rand(mesh.nE, 1), i)
+
+        f2 = EM.TDEM.FieldsTDEM(prb.mesh, 1, prb.nTimes, 'b')
+        for i in range(f2.nTimes):
+            f2.set_b(np.random.rand(mesh.nF, 1), i)
+            f2.set_e(np.random.rand(mesh.nE, 1), i)
+
+        V1 = f2.fieldVec().dot(prb.solveAh(sigma, f1).fieldVec())
+        V2 = f1.fieldVec().dot(prb.solveAht(sigma, f2).fieldVec())
+        self.assertLess(np.abs(V1-V2)/np.abs(V1), 1e-8)
+
+        
 
 
 if __name__ == '__main__':