diff --git a/mist.lua b/mist.lua
index 5400bfb..bba0854 100644
--- a/mist.lua
+++ b/mist.lua
@@ -1459,7 +1459,7 @@ do -- the main scope
 				end
 				
 			elseif newCat == 'GROUND_UNIT' then
-				if not unitData.playerCanDrive then
+				if nil == unitData.playerCanDrive then
 					unitData.playerCanDrive = true
 				end
 			
diff --git a/mist_4_4_83.lua b/mist_4_4_83.lua
index b93faeb..be6302b 100644
--- a/mist_4_4_83.lua
+++ b/mist_4_4_83.lua
@@ -1459,7 +1459,7 @@ do -- the main scope
 				end
 				
 			elseif newCat == 'GROUND_UNIT' then
-				if not unitData.playerCanDrive then
+				if nil == unitData.playerCanDrive then
 					unitData.playerCanDrive = true
 				end