Index: firmware/App/Controllers/SubstitutionPump.c
===================================================================
diff -u -r09bb4a7c085a868d1eb6d886c94ac6c78e5e92de -r7ef41d90338528f3e8c0ef801fc17fa1ec4b34ea
--- firmware/App/Controllers/SubstitutionPump.c	(.../SubstitutionPump.c)	(revision 09bb4a7c085a868d1eb6d886c94ac6c78e5e92de)
+++ firmware/App/Controllers/SubstitutionPump.c	(.../SubstitutionPump.c)	(revision 7ef41d90338528f3e8c0ef801fc17fa1ec4b34ea)
@@ -316,7 +316,8 @@
 {
     F32 speedIncrease;
     BOOL hasTgtBeenReached  = FALSE;
-    F32 currentToTargetDiff = fabs( getSubstitutionPumpTargetRate( pumpId ) - substitutionPumps[ pumpId ].currentPumpSpeed );
+    F32 pumpTargetSpeed = getSubstitutionPumpTargetRate( pumpId ) * SUBSTITUTION_PUMP_VOLUME_PER_REV; // Translate from ml/min to RPM.
+    F32 currentToTargetDiff = fabs( pumpTargetSpeed - substitutionPumps[ pumpId ].currentPumpSpeed );
 
     if ( currentToTargetDiff > NEARLY_ZERO )
     {
@@ -331,15 +332,15 @@
         }
 
         // Subtract current speed when target speed is smaller
-        if ( getSubstitutionPumpTargetRate( pumpId ) < substitutionPumps[ pumpId ].currentPumpSpeed )
+        if ( pumpTargetSpeed < substitutionPumps[ pumpId ].currentPumpSpeed )
         {
             speedIncrease *= -1.0F;
         }
 
         substitutionPumps[ pumpId ].currentPumpSpeed += speedIncrease;
 
         // If the pump's target speed is set to be 0, do not ramp down set it to zero immediately
-        if ( getSubstitutionPumpTargetRate( pumpId ) < NEARLY_ZERO )
+        if ( pumpTargetSpeed < NEARLY_ZERO )
         {
             substitutionPumps[ pumpId ].currentPumpSpeed = 0.0F;
         }