diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index 5d44d54..c9f688f 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -107,8 +107,9 @@
     "BC_DEAD_BINDER_DONE"
 };
 
-static const char* getReturnString(size_t idx)
+static const char* getReturnString(uint32_t cmd)
 {
+    size_t idx = cmd & 0xff;
     if (idx < sizeof(kReturnStrings) / sizeof(kReturnStrings[0]))
         return kReturnStrings[idx];
     else