diff --git a/src/l3d.h b/src/l3d.h
index 9bea983..dbe1113 100644
--- a/src/l3d.h
+++ b/src/l3d.h
@@ -46,7 +46,7 @@ public:
   static double GetGameTime(void)             { return gameTime; }
   static void   SetTimeAccel(float s);
   static float  GetTimeAccel(void)            { return timeAccel; }
-  static float  GetTimeStep(void)             { return timeAccel*frameTime; }
+  static float  GetTimeStep(void)             { return timeAccel*(1.0/62.5); }
   static int    GetScrWidth(void)             { return scrWidth; }
   static int    GetScrHeight(void)            { return scrHeight; }
   static int    GetScrAspect(void)            { return scrAspect; }
diff --git a/src/main.cpp b/src/main.cpp
index 14163a9..212a5e1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -275,8 +275,10 @@ void L3D::MainLoop(void) {
 
   Uint32 last_stats = SDL_GetTicks();
   int frame_stat = 0;
+  int phys_stat = 0;
   char fps_readout[32];
   Uint32 time_before_frame = SDL_GetTicks();
+  Uint32 last_phys_update = time_before_frame;
 
   for(;;) {
     frame_stat++;
@@ -315,19 +317,22 @@ void L3D::MainLoop(void) {
     //if(glGetError()) printf("GL: %s\n", gluErrorString(glGetError()));
 
     L3D::frameTime = 0.001*(SDL_GetTicks() - time_before_frame);
-    float step = L3D::timeAccel * L3D::frameTime;
 
     time_before_frame = SDL_GetTicks();
-    /* Game state update stuff. */
-    if(step) {
+    /* Fixed 62.5hz physics. */
+    while(time_before_frame - last_phys_update > 16) {
+      last_phys_update += 16;
+      const float step = L3D::GetTimeStep();
       Space::TimeStep(step);
       gameTime += step;
+      phys_stat++;
     }
     currentView->Update();
 
     if(SDL_GetTicks() - last_stats > 1000) {
-      snprintf(fps_readout, sizeof(fps_readout), "%d fps", frame_stat);
+      snprintf(fps_readout, sizeof(fps_readout), "%d fps, %d phys updates", frame_stat, phys_stat);
       frame_stat = 0;
+      phys_stat = 0;
       last_stats += 1000;
     }
   }