diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 51c7059..c3b2159 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -1058,6 +1058,8 @@
     case PIXEL_FORMAT_BGRA_8888:    return String8("BGRA_8888");
     case PIXEL_FORMAT_sRGB_A_8888:  return String8("sRGB_A_8888");
     case PIXEL_FORMAT_sRGB_X_8888:  return String8("sRGB_x_8888");
+    case HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED:
+                                    return String8("ImplDef");
     default:
         String8 result;
         result.appendFormat("? %08x", format);