diff --git a/tracetools/include/tracetools/tracetools.h b/tracetools/include/tracetools/tracetools.h
index fe040a2..d00d4dd 100644
--- a/tracetools/include/tracetools/tracetools.h
+++ b/tracetools/include/tracetools/tracetools.h
@@ -157,8 +157,8 @@ void TRACEPOINT(
  */
 void TRACEPOINT(
   rclcpp_callback_register,
-  const void * handle,
-  const void * callback);
+  const void * callback,
+  const void * function_target);
 
 #ifdef __cplusplus
 }
diff --git a/tracetools/lttng/tp_call.tp b/tracetools/lttng/tp_call.tp
index 1a833c9..4a964cd 100644
--- a/tracetools/lttng/tp_call.tp
+++ b/tracetools/lttng/tp_call.tp
@@ -224,11 +224,11 @@ TRACEPOINT_EVENT(
     ros2,
     rclcpp_callback_register,
     TP_ARGS(
-        const void *, handle_arg,
-        const char *, callback_arg
+        const void *, callback_arg,
+        const char *, symbol_arg
     ),
     TP_FIELDS(
-        ctf_integer_hex(const void *, handle, handle_arg)
-        ctf_string(callback, callback_arg)
+        ctf_integer_hex(const void *, callback, callback_arg)
+        ctf_string(symbol, symbol_arg)
     )
 )
diff --git a/tracetools/src/tracetools.c b/tracetools/src/tracetools.c
index dea60bc..b27f290 100644
--- a/tracetools/src/tracetools.c
+++ b/tracetools/src/tracetools.c
@@ -12,12 +12,16 @@
 
 const char * get_symbol(const void * function_ptr) {
 #if defined(WITH_LTTNG) && !defined(_WIN32)
-	char** symbols = backtrace_symbols(&function_ptr, 1);
-	const char * result = symbols[0];
-	free(symbols);
-	return result;
+  // If it's actually a lambda
+  if (NULL == function_ptr) {
+    return "";
+  }
+  char ** symbols = backtrace_symbols(&function_ptr, 1);
+  const char * result = symbols[0];
+  free(symbols);
+  return result;
 #else
-	return "";
+  return "";
 #endif
 }
 
@@ -166,8 +170,8 @@ void TRACEPOINT(
 
 void TRACEPOINT(
   rclcpp_callback_register,
-  const void * handle,
-  const void * callback)
+  const void * callback,
+  const void * function_target)
 {
-  CONDITIONAL_TP(ros2, rclcpp_callback_register, handle, get_symbol(callback));
+  CONDITIONAL_TP(ros2, rclcpp_callback_register, callback, get_symbol(function_target));
 }