diff --git a/canny_edge_machine.cpp b/canny_edge_machine.cpp
index 58c5e3c..d67de1b 100644
--- a/canny_edge_machine.cpp
+++ b/canny_edge_machine.cpp
@@ -175,7 +175,8 @@ class CannyEdgeMachine {
       //
       // cos(pi/8) -sin(pi/8)
       // sin(pi/8) cos(pi/8)
-      double octangle = 3.141592/8; // I know ...
+      // TODO: Move these somewhere else!
+      double octangle = M_PI/8;
       double cosoct = cos(octangle);
       double sinoct = sin(octangle);
       double neg_sinoct = -sinoct;
@@ -298,10 +299,14 @@ class CannyEdgeMachine {
     };
     
     void doSecondStep(void) {
+      // Reset maximum_magnitude since it will be rebuilt here
+      for(int i=0; i<this->pixels; i++) this->maximum_magnitude[i] = 0;
       this->filterLocalMaxima(); // uses t_low only
     };
     
     void doThirdStep(void) {
+      // Reset binary_edge_pixels since they will be rebuilt here
+      for(int i=0; i<this->pixels; i++) this->binary_edge_pixels[i] = 0;
       this->workLocalMaxima(); // uses t_low & t_high
       this->showEdges();      
     };