diff --git a/ownlang-core/src/main/java/com/annimon/ownlang/exceptions/OwnLangRuntimeException.java b/ownlang-core/src/main/java/com/annimon/ownlang/exceptions/OwnLangRuntimeException.java
index d121281..b85c0df 100644
--- a/ownlang-core/src/main/java/com/annimon/ownlang/exceptions/OwnLangRuntimeException.java
+++ b/ownlang-core/src/main/java/com/annimon/ownlang/exceptions/OwnLangRuntimeException.java
@@ -3,7 +3,7 @@ package com.annimon.ownlang.exceptions;
 /**
  * Base type for all runtime exceptions
  */
-public abstract class OwnLangRuntimeException extends RuntimeException {
+public class OwnLangRuntimeException extends RuntimeException {
 
     public OwnLangRuntimeException() {
         super();
@@ -12,4 +12,8 @@ public abstract class OwnLangRuntimeException extends RuntimeException {
     public OwnLangRuntimeException(String message) {
         super(message);
     }
+
+    public OwnLangRuntimeException(String message, Throwable ex) {
+        super(message, ex);
+    }
 }
\ No newline at end of file
diff --git a/ownlang-core/src/main/java/com/annimon/ownlang/lib/CallStack.java b/ownlang-core/src/main/java/com/annimon/ownlang/lib/CallStack.java
index eec2060..5a0b00d 100644
--- a/ownlang-core/src/main/java/com/annimon/ownlang/lib/CallStack.java
+++ b/ownlang-core/src/main/java/com/annimon/ownlang/lib/CallStack.java
@@ -14,7 +14,7 @@ public final class CallStack {
     }
     
     public static synchronized void enter(String name, Function function) {
-        calls.push(new CallInfo(name, function));
+        calls.push(new CallInfo(name, function.toString()));
     }
     
     public static synchronized void exit() {
@@ -25,10 +25,10 @@ public final class CallStack {
         return calls;
     }
     
-    public record CallInfo(String name, Function function) {
+    public record CallInfo(String name, String function) {
         @Override
         public String toString() {
-            return String.format("%s: %s", name, function.toString().trim());
+            return String.format("%s: %s", name, function);
         }
     }
 }
diff --git a/ownlang-parser/src/main/java/com/annimon/ownlang/parser/ast/FunctionalExpression.java b/ownlang-parser/src/main/java/com/annimon/ownlang/parser/ast/FunctionalExpression.java
index 0ffc833..663e865 100644
--- a/ownlang-parser/src/main/java/com/annimon/ownlang/parser/ast/FunctionalExpression.java
+++ b/ownlang-parser/src/main/java/com/annimon/ownlang/parser/ast/FunctionalExpression.java
@@ -1,9 +1,6 @@
 package com.annimon.ownlang.parser.ast;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
-import com.annimon.ownlang.exceptions.TypeException;
-import com.annimon.ownlang.exceptions.VariableDoesNotExistsException;
-import com.annimon.ownlang.exceptions.UnknownFunctionException;
+import com.annimon.ownlang.exceptions.*;
 import com.annimon.ownlang.lib.*;
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -42,13 +39,9 @@ public final class FunctionalExpression extends InterruptableNode implements Exp
         }
         final Function f = consumeFunction(functionExpr);
         CallStack.enter(functionExpr.toString(), f);
-        try {
-            final Value result = f.execute(values);
-            CallStack.exit();
-            return result;
-        } catch (ArgumentsMismatchException | TypeException | VariableDoesNotExistsException ex) {
-            throw new RuntimeException(ex.getMessage() + " in function " + functionExpr, ex);
-        }
+        final Value result = f.execute(values);
+        CallStack.exit();
+        return result;
     }
     
     private Function consumeFunction(Expression expr) {