diff --git a/src/main/java/astGenerator/ASTGenerator.java b/src/main/java/astGenerator/ASTGenerator.java
index c4bb951..3d7d34e 100644
--- a/src/main/java/astGenerator/ASTGenerator.java
+++ b/src/main/java/astGenerator/ASTGenerator.java
@@ -206,8 +206,12 @@ public class ASTGenerator extends DecafBaseVisitor<Node> {
         for(DecafParser.ReceivingMethodContext receivingMethod: ctx.receivingMethod()) {
             receivingMethods.add((ReceivingMethod) visit(receivingMethod));
         }
-        Receiver receiver = (Receiver) visit(ctx.receiver());
-        return new MethodCallStatementExpression(methodName, receiver, receivingMethods, arguments);
+        if (ctx.receiver() != null) {
+            Receiver receiver = (Receiver) visit(ctx.receiver());
+            return new MethodCallStatementExpression(methodName, receiver, receivingMethods, arguments);
+        } else {
+            return new MethodCallStatementExpression(methodName, null, receivingMethods, arguments);
+        }
     }
 
     @Override