diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index c4ea8cc..2d63bde 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -821,7 +821,7 @@
     return NO_ERROR;
 }
 
-sp<Fence> HWComposer::getLastRetireFence(int32_t id) {
+sp<Fence> HWComposer::getLastRetireFence(int32_t id) const {
     if (uint32_t(id)>31 || !mAllocatedDisplayIDs.hasBit(id))
         return Fence::NO_FENCE;
     return mDisplayData[id].lastRetireFence;
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 9218bf6..e93bb7e 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -142,7 +142,7 @@
     // signal when the h/w composer is completely finished with the frame.
     // For physical displays, it is no longer being displayed. For virtual
     // displays, writes to the output buffer are complete.
-    sp<Fence> getLastRetireFence(int32_t id);
+    sp<Fence> getLastRetireFence(int32_t id) const;
 
     /*
      * Interface to hardware composer's layers functionality.