diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c
index 467f371cb01..54839ffb6a4 100644
--- a/lib/libalias/alias.c
+++ b/lib/libalias/alias.c
@@ -1425,6 +1425,10 @@ PacketAliasOut(char *ptr,           /* valid IP packet */
             SetDefaultAliasAddress(pip->ip_src);
         }
     }
+    else if (packetAliasMode & PKT_ALIAS_PROXY_ONLY)
+    {
+        SetDefaultAliasAddress(pip->ip_src);
+    }
 
     iresult = PKT_ALIAS_IGNORED;
     if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0)
diff --git a/sys/netinet/libalias/alias.c b/sys/netinet/libalias/alias.c
index 467f371cb01..54839ffb6a4 100644
--- a/sys/netinet/libalias/alias.c
+++ b/sys/netinet/libalias/alias.c
@@ -1425,6 +1425,10 @@ PacketAliasOut(char *ptr,           /* valid IP packet */
             SetDefaultAliasAddress(pip->ip_src);
         }
     }
+    else if (packetAliasMode & PKT_ALIAS_PROXY_ONLY)
+    {
+        SetDefaultAliasAddress(pip->ip_src);
+    }
 
     iresult = PKT_ALIAS_IGNORED;
     if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0)