diff -r cea0a28d50fd -r 7e65c276ca2d src/mem/cache/base.hh
--- a/src/mem/cache/base.hh	Fri Oct 30 10:32:46 2015 +0000
+++ b/src/mem/cache/base.hh	Fri Oct 30 10:33:01 2015 +0000
@@ -508,9 +508,12 @@
 
     MSHR *allocateWriteBuffer(PacketPtr pkt, Tick time)
     {
-        // should only see clean evictions in a read-only cache
-        assert(!isReadOnly || pkt->cmd == MemCmd::CleanEvict);
-        assert(pkt->isWrite() && !pkt->isRead());
+        // should only see writes or clean evicts here
+        assert(pkt->isWrite() || pkt->cmd == MemCmd::CleanEvict);
+
+        // if this is a read-only cache we should never see any writes
+        assert(!(isReadOnly && pkt->isWrite()));
+
         return allocateBufferInternal(&writeBuffer,
                                       blockAlign(pkt->getAddr()), blkSize,
                                       pkt, time, true);
diff -r cea0a28d50fd -r 7e65c276ca2d src/mem/packet.cc
--- a/src/mem/packet.cc	Fri Oct 30 10:32:46 2015 +0000
+++ b/src/mem/packet.cc	Fri Oct 30 10:33:01 2015 +0000
@@ -88,7 +88,7 @@
     { SET4(IsWrite, NeedsExclusive, IsRequest, HasData),
             InvalidCmd, "Writeback" },
     /* CleanEvict */
-    { SET2(IsWrite, IsRequest), InvalidCmd, "CleanEvict" },
+    { SET1(IsRequest), InvalidCmd, "CleanEvict" },
     /* SoftPFReq */
     { SET4(IsRead, IsRequest, IsSWPrefetch, NeedsResponse),
             SoftPFResp, "SoftPFReq" },