diff --git a/image_analysis/bragg_prediction/BraggPredictionRotation.cpp b/image_analysis/bragg_prediction/BraggPredictionRotation.cpp
index 23315bba..a1305e52 100644
--- a/image_analysis/bragg_prediction/BraggPredictionRotation.cpp
+++ b/image_analysis/bragg_prediction/BraggPredictionRotation.cpp
@@ -27,6 +27,8 @@ namespace {
     inline int solve_trig(float A, float B, float D,
                           float phi0, float phi1,
                           float out_phi[2]) {
+        if (phi1 < phi0) std::swap(phi0, phi1);
+
         const float R = std::sqrt(A*A + B*B);
         if (!(R > 0.0f))
             return 0;
diff --git a/image_analysis/bragg_prediction/BraggPredictionRotation.h b/image_analysis/bragg_prediction/BraggPredictionRotation.h
index 6c4de590..a411f3d5 100644
--- a/image_analysis/bragg_prediction/BraggPredictionRotation.h
+++ b/image_analysis/bragg_prediction/BraggPredictionRotation.h
@@ -15,7 +15,7 @@
 
 class BraggPredictionRotation : public BraggPrediction {
 public:
-    BraggPredictionRotation(int max_reflections);
+    BraggPredictionRotation(int max_reflections = 200*200*200);
 
     int Calc(const DiffractionExperiment &experiment,
              const CrystalLattice &lattice,