diff --git a/Code/Mantid/Framework/Crystal/src/PredictPeaks.cpp b/Code/Mantid/Framework/Crystal/src/PredictPeaks.cpp
index 1e195549ef217caac3b1a6c3d3080fedd27c91d9..0a03cfdb7a5b19bdf7368c2b08fd0d1d6c199472 100644
--- a/Code/Mantid/Framework/Crystal/src/PredictPeaks.cpp
+++ b/Code/Mantid/Framework/Crystal/src/PredictPeaks.cpp
@@ -318,7 +318,7 @@ namespace Crystal
     {
       // ---------------- Determine which HKL to look for -------------------------------------
       // Inverse d-spacing that is the limit to look for.
-      double dstar = 1.0/minD;
+      double Qmax = 2.*M_PI/minD;
       V3D hklMin(0,0,0);
       V3D hklMax(0,0,0);
       for (double qx=-1; qx < 2; qx += 2)
@@ -327,7 +327,7 @@ namespace Crystal
           {
             // Build a q-vector for this corner of a cube
             V3D Q(qx,qy,qz);
-            Q *= dstar;
+            Q *= Qmax;
             V3D hkl = crystal.hklFromQ(Q);
             // Find the limits of each hkl
             for (size_t i=0; i<3; i++)
diff --git a/Code/Mantid/Framework/Geometry/src/Crystal/OrientedLattice.cpp b/Code/Mantid/Framework/Geometry/src/Crystal/OrientedLattice.cpp
index e1b5647249f0e023bb18d4375c9ad3fb107d5f5e..cecae936264076e9058a85afce83013fa9d98167 100644
--- a/Code/Mantid/Framework/Geometry/src/Crystal/OrientedLattice.cpp
+++ b/Code/Mantid/Framework/Geometry/src/Crystal/OrientedLattice.cpp
@@ -163,7 +163,7 @@ namespace Geometry
   {
     DblMatrix UBinv = this->getUB();
     UBinv.Invert();
-    V3D out = UBinv*Q; //transform back to HKL
+    V3D out = UBinv*Q/TWO_PI; //transform back to HKL
     return out;
   }
 
diff --git a/Code/Mantid/Framework/Geometry/test/OrientedLatticeTest.h b/Code/Mantid/Framework/Geometry/test/OrientedLatticeTest.h
index 2ea23bcbbb699cd4ff60b10d61fea8bf5780ceea..a2006de288f493c1149fbd1232cb24d7337fe006 100644
--- a/Code/Mantid/Framework/Geometry/test/OrientedLatticeTest.h
+++ b/Code/Mantid/Framework/Geometry/test/OrientedLatticeTest.h
@@ -41,7 +41,7 @@ public:
     // Convert to and from HKL
     V3D hkl = u.hklFromQ(V3D(1.0, 2.0, 3.0));
     double dstar = u.dstar(hkl[0], hkl[1], hkl[2]);
-    TS_ASSERT_DELTA( dstar, sqrt(1+4.0+9.0), 1e-4); // The d-spacing after a round trip matches the Q we put in
+    TS_ASSERT_DELTA( dstar, .5*sqrt(1+4.0+9.0)/M_PI, 1e-4); // The d-spacing after a round trip matches the Q we put in
   }