diff --git a/libs/acn/RPTRequestPDU.cpp b/libs/acn/RPTRequestPDU.cpp
index 577e382b1..db6179755 100644
--- a/libs/acn/RPTRequestPDU.cpp
+++ b/libs/acn/RPTRequestPDU.cpp
@@ -30,6 +30,11 @@ using ola::io::OutputStream;
 using ola::network::HostToNetwork;
 
 void RPTRequestPDU::PrependPDU(ola::io::IOStack *stack) {
+  if (!stack) {
+    OLA_WARN << "RPTRequestPDU::PrependPDU: missing stack";
+    return;
+  }
+
   uint32_t vector = HostToNetwork(
       static_cast<uint32_t>(VECTOR_REQUEST_RDM_CMD));
   stack->Write(reinterpret_cast<uint8_t*>(&vector), sizeof(vector));
diff --git a/libs/acn/RPTRequestPDUTest.cpp b/libs/acn/RPTRequestPDUTest.cpp
index d04b88712..f40b30b7a 100644
--- a/libs/acn/RPTRequestPDUTest.cpp
+++ b/libs/acn/RPTRequestPDUTest.cpp
@@ -139,6 +139,10 @@ void RPTRequestPDUTest::testPrepend() {
     0, 0, 0, 0x01
   };
   OLA_ASSERT_DATA_EQUALS(expected_data, sizeof(expected_data), buffer, length);
+
+  // test null stack
+  RPTRequestPDU::PrependPDU(NULL);
+
   delete[] buffer;
 }
 }  // namespace acn