diff --git a/src/me/topchetoeu/jscript/engine/Engine.java b/src/me/topchetoeu/jscript/engine/Engine.java
index dd6b1d2..773ec9f 100644
--- a/src/me/topchetoeu/jscript/engine/Engine.java
+++ b/src/me/topchetoeu/jscript/engine/Engine.java
@@ -69,6 +69,17 @@ public class Engine implements DebugController {
     private final HashMap<Filename, TreeSet<Location>> bpts = new HashMap<>();
     private final HashMap<Filename, SourceMap> maps = new HashMap<>();
 
+    public Location mapToCompiled(Location location) {
+        var map = maps.get(location.filename());
+        if (map == null) return location;
+        return map.toCompiled(location);
+    }
+    public Location mapToOriginal(Location location) {
+        var map = maps.get(location.filename());
+        if (map == null) return location;
+        return map.toOriginal(location);
+    }
+
     private DebugController debugger;
     private Thread thread;
     private PriorityBlockingQueue<Task> tasks = new PriorityBlockingQueue<>();
diff --git a/src/me/topchetoeu/jscript/engine/debug/SimpleDebugger.java b/src/me/topchetoeu/jscript/engine/debug/SimpleDebugger.java
index c8faa18..5143ad7 100644
--- a/src/me/topchetoeu/jscript/engine/debug/SimpleDebugger.java
+++ b/src/me/topchetoeu/jscript/engine/debug/SimpleDebugger.java
@@ -67,14 +67,12 @@ public class SimpleDebugger implements Debugger {
         public final Filename filename;
         public final String source;
         public final TreeSet<Location> breakpoints;
-        public final SourceMap map;
 
-        public Source(int id, Filename filename, String source, TreeSet<Location> breakpoints, SourceMap map) {
+        public Source(int id, Filename filename, String source, TreeSet<Location> breakpoints) {
             this.id = id;
             this.filename = filename;
             this.source = source;
             this.breakpoints = breakpoints;
-            this.map = map;
         }
     }
     private static class Breakpoint {
@@ -234,21 +232,6 @@ public class SimpleDebugger implements Debugger {
         return nextId++;
     }
 
-    private Location toCompiled(Location location) {
-        var id = filenameToId.get(location.filename());
-        if (id == null) return location;
-        var map = idToSource.get(id).map;
-        if (map == null) return location;
-        return map.toCompiled(location);
-    }
-    private Location toOriginal(Location location) {
-        var id = filenameToId.get(location.filename());
-        if (id == null) return location;
-        var map = idToSource.get(id).map;
-        if (map == null) return location;
-        return map.toOriginal(location);
-    }
-
     private synchronized void updateFrames(Context ctx) {
         var frame = ctx.peekFrame();
         if (frame == null) return;
@@ -858,7 +841,7 @@ public class SimpleDebugger implements Debugger {
 
     @Override public void onSource(Filename filename, String source, TreeSet<Location> locations, SourceMap map) {
         int id = nextId();
-        var src = new Source(id, filename, source, locations, map);
+        var src = new Source(id, filename, source, locations);
 
         idToSource.put(id, src);
         filenameToId.put(filename, id);
@@ -887,7 +870,7 @@ public class SimpleDebugger implements Debugger {
 
             if (!frame.debugData) return false;
 
-            if (instruction.location != null) frame.updateLoc(toCompiled(instruction.location));
+            if (instruction.location != null) frame.updateLoc(ctx.engine.mapToCompiled(instruction.location));
             loc = frame.location;
             isBreakpointable = loc != null && (instruction.breakpoint.shouldStepIn());
 
diff --git a/src/me/topchetoeu/jscript/exceptions/EngineException.java b/src/me/topchetoeu/jscript/exceptions/EngineException.java
index e63169f..c76502b 100644
--- a/src/me/topchetoeu/jscript/exceptions/EngineException.java
+++ b/src/me/topchetoeu/jscript/exceptions/EngineException.java
@@ -12,19 +12,44 @@ import me.topchetoeu.jscript.engine.values.Values;
 import me.topchetoeu.jscript.engine.values.ObjectValue.PlaceholderProto;
 
 public class EngineException extends RuntimeException {
+    public static class StackElement {
+        public final Location location;
+        public final String function;
+
+        public String toString(Context ctx) {
+            var res = "";
+            var loc = location;
+
+            if (loc != null && ctx != null && ctx.engine != null) loc = ctx.engine.mapToCompiled(loc);
+
+            if (loc != null) res += "at " + loc.toString() + " ";
+            if (function != null && !function.equals("")) res += "in " + function + " ";
+
+            return res.trim();
+        }
+        @Override public String toString() {
+            return toString(null);
+        }
+
+        public StackElement(Location location, String function) {
+            if (function != null) function = function.trim();
+            if (function.equals("")) function = null;
+
+            this.location = location;
+            this.function = function;
+        }
+    }
+
     public final Object value;
     public EngineException cause;
     public Environment env = null;
     public Engine engine = null;
-    public final List<String> stackTrace = new ArrayList<>();
+    public final List<StackElement> stackTrace = new ArrayList<>();
 
     public EngineException add(String name, Location location) {
-        var res = "";
-
-        if (location != null) res += "at " + location.toString() + " ";
-        if (name != null && !name.equals("")) res += "in " + name + " ";
-
-        this.stackTrace.add(res.trim());
+        var el = new StackElement(location, name);
+        if (el.function == null && el.location == null) return this;
+        stackTrace.add(el);
         return this;
     }
     public EngineException setCause(EngineException cause) {
@@ -46,7 +71,7 @@ public class EngineException extends RuntimeException {
             ss.append("[Error while stringifying]\n");
         }
         for (var line : stackTrace) {
-            ss.append("    ").append(line).append('\n');
+            ss.append("    ").append(line.toString(ctx)).append("\n");
         }
         if (cause != null) ss.append("Caused by ").append(cause.toString(ctx)).append('\n');
         ss.deleteCharAt(ss.length() - 1);