diff --git a/ElectricMachines/im.pro b/ElectricMachines/im.pro
index 5e4c0e654da00076724d0e3d287bc2bc8cf42ee5..ea74cbda854429a6e14102ebb1f9ec317b7cbf02 100644
--- a/ElectricMachines/im.pro
+++ b/ElectricMachines/im.pro
@@ -15,15 +15,12 @@ DefineConstant[
     Name "Input/41Source type in stator", Highlight "Blue"},
   Flag_Cir_RotorCage = { (Flag_SrcType_Stator==2), Choices{0,1},
     Name "Input/40Use circuit in rotor cage", ReadOnly (Flag_SrcType_Stator==1)}
-  slip = { 0, Min 0., Max 1, Step 0.02, Loop (Flag_AnalysisType == 2),
+  slip = { 0, Min 0., Max 1, Step 0.02, Loop (Flag_AnalysisType == 2 && TotalMemory > 4096),
     Name "Input/30Slip", Highlight "AliceBlue", Visible (Flag_AnalysisType == 2)}
 ];
 
 Flag_Cir = (Flag_SrcType_Stator==2);
 
-If(Flag_AnalysisType!=2)
-  UndefineConstant[ "Input/30Slip" ];
-EndIf
 variableFrequencyLoop = slip;
 
 DefineConstant[
diff --git a/ElectricMachines/im_3kW.pro b/ElectricMachines/im_3kW.pro
index 1fef895fa92401e66257f73f955f6f1d61f76363..d00d7282d6284c0fc090adecfdb4e0eeb722a97f 100644
--- a/ElectricMachines/im_3kW.pro
+++ b/ElectricMachines/im_3kW.pro
@@ -15,16 +15,12 @@ DefineConstant[
     Name "Input/41Source type in stator", Highlight "Blue"},
   Flag_Cir_RotorCage = { 0 , Choices{0,1},
     Name "Input/40Use circuit in rotor cage", ReadOnly (Flag_SrcType_Stator==1)}
-  slip = { 0, Min 0., Max 1, Step 0.05, Loop (Flag_AnalysisType == 2),
+  slip = { 0, Min 0., Max 1, Step 0.05, Loop (Flag_AnalysisType == 2 && TotalMemory > 4096),
     Name "Input/30Slip", Highlight "AliceBlue", Visible (Flag_AnalysisType == 2)}
 ];
 
 Flag_Cir = (Flag_SrcType_Stator==2);
 
-// this not necessary anymore (thanks to the new behavior of Visibility)
-If(Flag_AnalysisType!=2)
-  UndefineConstant[ "Input/30Slip" ];
-EndIf
 variableFrequencyLoop = slip;
 
 DefineConstant[