diff --git a/src/sequence_diagram/visitor/call_expression_context.cc b/src/sequence_diagram/visitor/call_expression_context.cc
index 784db53a..a936dae2 100644
--- a/src/sequence_diagram/visitor/call_expression_context.cc
+++ b/src/sequence_diagram/visitor/call_expression_context.cc
@@ -177,7 +177,8 @@ void call_expression_context::enter_lambda_expression(std::int64_t id)
 
 void call_expression_context::leave_lambda_expression()
 {
-    assert(!current_lambda_caller_id_.empty());
+    if(current_lambda_caller_id_.empty())
+        return;
 
     LOG_DBG("Leaving current lambda expression id to {}",
         current_lambda_caller_id_.top());