diff --git a/src/SquidConfig.h b/src/SquidConfig.h
index ae2d72cc763..a21f7b16bad 100644
--- a/src/SquidConfig.h
+++ b/src/SquidConfig.h
@@ -243,7 +243,7 @@ class SquidConfig
     } Addrs;
     size_t tcpRcvBufsz;
     size_t udpMaxHitObjsz;
-    wordlist *mcast_group_list;
+    SBufList mcast_group_list;
     CachePeers *peers;
     int npeers;
 
diff --git a/src/cf.data.pre b/src/cf.data.pre
index 898fc9af48d..16addd4c507 100644
--- a/src/cf.data.pre
+++ b/src/cf.data.pre
@@ -8753,7 +8753,7 @@ COMMENT_START
 COMMENT_END
 
 NAME: mcast_groups
-TYPE: wordlist
+TYPE: SBufList
 LOC: Config.mcast_group_list
 DEFAULT: none
 DOC_START
diff --git a/src/icp_v2.cc b/src/icp_v2.cc
index cc9c76306f9..2b82e21f56b 100644
--- a/src/icp_v2.cc
+++ b/src/icp_v2.cc
@@ -739,8 +739,10 @@ icpIncomingConnectionOpened(Ipc::StartListeningAnswer &answer)
 
     Comm::SetSelect(conn->fd, COMM_SELECT_READ, icpHandleUdp, nullptr, 0);
 
-    for (const wordlist *s = Config.mcast_group_list; s; s = s->next)
-        ipcache_nbgethostbyname(s->key, mcastJoinGroups, nullptr); // XXX: pass the conn for mcastJoinGroups usage.
+    for (const auto &groupName : Config.mcast_group_list) {
+        SBuf tmp(groupName); // XXX: c_str() may reallocate
+        ipcache_nbgethostbyname(tmp.c_str(), mcastJoinGroups, nullptr); // XXX: pass the conn for mcastJoinGroups usage.
+    }
 
     debugs(12, DBG_IMPORTANT, "Accepting ICP messages on " << conn->local);