diff --git a/rcl/src/rcl/subscription.c b/rcl/src/rcl/subscription.c
index 6a4af49..9dd9ed8 100644
--- a/rcl/src/rcl/subscription.c
+++ b/rcl/src/rcl/subscription.c
@@ -203,6 +203,7 @@ fail:
     }
 
     allocator->deallocate(subscription->impl, allocator->state);
+    subscription->impl = NULL;
   }
   ret = fail_ret;
   // Fall through to cleanup
@@ -238,6 +239,7 @@ rcl_subscription_fini(rcl_subscription_t * subscription, rcl_node_t * node)
       result = RCL_RET_ERROR;
     }
     allocator.deallocate(subscription->impl, allocator.state);
+    subscription->impl = NULL;
   }
   RCUTILS_LOG_DEBUG_NAMED(ROS_PACKAGE_NAME, "Subscription finalized");
   return result;
@@ -301,10 +303,6 @@ rcl_take_sequence(
   rmw_subscription_allocation_t * allocation
 )
 {
-  // Set the sizes to zero to indicate that there are no valid messages
-  message_sequence->size = 0u;
-  message_info_sequence->size = 0u;
-
   RCUTILS_LOG_DEBUG_NAMED(ROS_PACKAGE_NAME, "Subscription taking %zu messages", count);
   if (!rcl_subscription_is_valid(subscription)) {
     return RCL_RET_SUBSCRIPTION_INVALID;  // error message already set
@@ -322,6 +320,10 @@ rcl_take_sequence(
     return RCL_RET_INVALID_ARGUMENT;
   }
 
+  // Set the sizes to zero to indicate that there are no valid messages
+  message_sequence->size = 0u;
+  message_info_sequence->size = 0u;
+
   size_t taken = 0u;
   rmw_ret_t ret = rmw_take_sequence(
     subscription->impl->rmw_handle, count, message_sequence, message_info_sequence, &taken,
@@ -385,6 +387,7 @@ rcl_take_loaned_message(
   if (!rcl_subscription_is_valid(subscription)) {
     return RCL_RET_SUBSCRIPTION_INVALID;  // error already set
   }
+  RCL_CHECK_ARGUMENT_FOR_NULL(loaned_message, RCL_RET_INVALID_ARGUMENT);
   if (*loaned_message) {
     RCL_SET_ERROR_MSG("loaned message is already initialized");
     return RCL_RET_INVALID_ARGUMENT;