diff --git a/yield/parser/env/WorkEnv.hx b/yield/parser/env/WorkEnv.hx
index 3d203bc..55ab0c4 100644
--- a/yield/parser/env/WorkEnv.hx
+++ b/yield/parser/env/WorkEnv.hx
@@ -69,7 +69,7 @@ class WorkEnv {
 	public var yieldKeyword  (default, null):String;
 	public var yieldExplicit (default, null):Bool;
 	public var yieldExtend   (default, null):Bool;
-	public var positionMapping (default, never):Bool = #if (debug && !no_yield_follow_positions && (haxe_ver >= 4.000) || yield_position_mapping) true #else false #end;
+	public var positionMapping (default, never):Bool = #if ((haxe_ver >= 4.000) && (debug && !no_yield_follow_positions || yield_position_mapping)) true #else false #end;
 	
 	public var currentScope (default, null):Scope;
 	public var scopeCounter (default, null):UInt;