diff --git a/repos/base-sel4/doc/ipc_and_virt_mem.txt b/repos/base-sel4/doc/ipc_and_virt_mem.txt
index b379c2165..d29d35567 100644
--- a/repos/base-sel4/doc/ipc_and_virt_mem.txt
+++ b/repos/base-sel4/doc/ipc_and_virt_mem.txt
@@ -184,6 +184,13 @@ single RPC call.
 
 That said, the simple capability-delegation test works as expected.
 
+When repeatedly performing an IPC call with a delegated capability, the
+RECV_CAP index will be populated by the first call. Subsequent attempts to
+override the RECV_CAP capability do not work (the 'extraCaps' field of the
+received message info remains 0). The receiver has to make sure that the
+specified 'CapReceivePath' is an empty capability slot. I.e., by calling
+'seL4_CNode_Delete' prior 'seL4_Wait'.
+
 
 Translation of capabilities aka "unwrapping"
 ============================================
diff --git a/repos/base-sel4/src/test/sel4/main.cc b/repos/base-sel4/src/test/sel4/main.cc
index 2e87bfc9f..27d4d4d38 100644
--- a/repos/base-sel4/src/test/sel4/main.cc
+++ b/repos/base-sel4/src/test/sel4/main.cc
@@ -100,6 +100,9 @@ void second_thread_entry()
 	for (;;) {
 		seL4_SetCapReceivePath(seL4_CapInitThreadCNode, RECV_CAP, 32);
 
+		seL4_CNode_Delete(seL4_CapInitThreadCNode, RECV_CAP, 32);
+
+
 		PDBG("call seL4_Wait");
 		seL4_MessageInfo_t msg_info = seL4_Wait(EP_CAP, nullptr);
 		PDBG("returned from seL4_Wait, call seL4_Reply");
@@ -241,6 +244,17 @@ int main()
 		PDBG("returned from seL4_Call");
 	}
 
+	PDBG("seL4_Call, delegating a TCB capability");
+	{
+		seL4_MessageInfo_t msg_info = seL4_MessageInfo_new(13, 0, 1, 0);
+
+		seL4_SetCap(0, SECOND_THREAD_CAP);
+
+		seL4_Call(EP_CAP, msg_info);
+
+		PDBG("returned from seL4_Call");
+	}
+
 	PDBG("seL4_Call, delegating a minted endpoint capability");
 	{
 		/* mint EP_CAP into EP_MINTED_CAP */