diff --git a/src/mem/ruby/system/VIPERCoalescer.cc b/src/mem/ruby/system/VIPERCoalescer.cc
index d8977ac853..cdef2b1f3f 100644
--- a/src/mem/ruby/system/VIPERCoalescer.cc
+++ b/src/mem/ruby/system/VIPERCoalescer.cc
@@ -76,6 +76,16 @@ VIPERCoalescer::~VIPERCoalescer()
 {
 }
 
+void
+VIPERCoalescer::issueRequest(CoalescedRequest* crequest)
+{
+}
+
+void
+VIPERCoalescer::issueMemSyncRequest(PacketPtr pkt)
+{
+}
+
 // Places an uncoalesced packet in uncoalescedTable. If the packet is a
 // special type (MemFence, scoping, etc), it is issued immediately.
 RequestStatus
diff --git a/src/mem/ruby/system/VIPERCoalescer.hh b/src/mem/ruby/system/VIPERCoalescer.hh
index 2b6e86e0c1..814166df40 100644
--- a/src/mem/ruby/system/VIPERCoalescer.hh
+++ b/src/mem/ruby/system/VIPERCoalescer.hh
@@ -57,6 +57,9 @@ class VIPERCoalescer : public GPUCoalescer
     typedef VIPERCoalescerParams Params;
     VIPERCoalescer(const Params *);
     ~VIPERCoalescer();
+
+    void issueMemSyncRequest(PacketPtr pkt);
+    void issueRequest(CoalescedRequest* crequest) override;
     void wbCallback(Addr address);
     void invCallback(Addr address);
     RequestStatus makeRequest(PacketPtr pkt);