Index: firmware/App/Drivers/PeristalticPump.c
===================================================================
diff -u -r2bf661ae63145fbf02329d96fecb32b0aa7dbb44 -rbfbe825bef1c8544c37c20bbeaf61c0c27356096
--- firmware/App/Drivers/PeristalticPump.c	(.../PeristalticPump.c)	(revision 2bf661ae63145fbf02329d96fecb32b0aa7dbb44)
+++ firmware/App/Drivers/PeristalticPump.c	(.../PeristalticPump.c)	(revision bfbe825bef1c8544c37c20bbeaf61c0c27356096)
@@ -100,7 +100,7 @@
     U16 rotorRevsNow = getH4RotorRevsCounter();
 
     // Update measured pump motor speed.
-    if ( ( H4_ZERO_SPEED_PERIOD == period ) || ( H4_INVALID_SPEED_PERIOD == period ) )
+    if ( ( 0 == period ) || ( H4_INVALID_SPEED_PERIOD == period ) || ( H4_ZERO_SPEED_PERIOD == period ) )
     {
         pumpMeasSpeedRPM = 0.0F;
     }