diff --git a/LCS/Stream/include/Stream/SocketStream.h b/LCS/Stream/include/Stream/SocketStream.h
index b9eb71c77d88d6a38b50811ee23bc5e563fc15a2..c6834cc62781d90401ed1f1a2061393edc752aa1 100644
--- a/LCS/Stream/include/Stream/SocketStream.h
+++ b/LCS/Stream/include/Stream/SocketStream.h
@@ -66,7 +66,7 @@ class SocketStream : public FileDescriptorBasedStream
      * Returns the number of messages received if ok, or throws on syscall error
      */
     unsigned recvmmsg( void *bufBase, unsigned maxMsgSize,
-                       std::vector<unsigned> &recvdMsgSizes );
+                       std::vector<unsigned> &recvdMsgSizes ) const;
 
     // Allow individual recv()/send() calls to last for 'timeout' seconds before returning EWOULDBLOCK
     void setTimeout(double timeout);
diff --git a/LCS/Stream/src/SocketStream.cc b/LCS/Stream/src/SocketStream.cc
index 8acf9fd9aa3524fe12467e1fbac25889129810c5..cb8f43186f81b4776dbe3dc2118c04d09ecf9050 100644
--- a/LCS/Stream/src/SocketStream.cc
+++ b/LCS/Stream/src/SocketStream.cc
@@ -311,7 +311,7 @@ struct mmsghdr {
 #endif
 
 unsigned SocketStream::recvmmsg( void *bufBase, unsigned maxMsgSize,
-                                 std::vector<unsigned> &recvdMsgSizes )
+                                 std::vector<unsigned> &recvdMsgSizes ) const
 {
   ASSERT(protocol == UDP);
   ASSERT(mode == Server);