diff --git a/src/core/net/ip6.cpp b/src/core/net/ip6.cpp
index f9cbc3409..d555b10ec 100644
--- a/src/core/net/ip6.cpp
+++ b/src/core/net/ip6.cpp
@@ -651,6 +651,7 @@ Error Ip6::FragmentDatagram(Message &aMessage, uint8_t aIpProto)
         fragmentHeader.SetOffset(offset);
 
         VerifyOrExit((fragment = NewMessage(0)) != nullptr, error = kErrorNoBufs);
+        IgnoreError(fragment->SetPriority(aMessage.GetPriority()));
         SuccessOrExit(error = fragment->SetLength(aMessage.GetOffset() + sizeof(fragmentHeader) + payloadFragment));
 
         header.SetPayloadLength(payloadFragment + sizeof(fragmentHeader));