diff --git a/libcutils/mq.c b/libcutils/mq.c
index 6f6740e..899b1bc 100644
--- a/libcutils/mq.c
+++ b/libcutils/mq.c
@@ -579,7 +579,7 @@
 
 /** Prepare to read bytes from the peer. */
 static void peerProxyExpectBytes(PeerProxy* peerProxy, Header* header) {
-    ALOGD("Expecting %d bytes.", header->size);
+    ALOGD("Expecting %zd bytes.", header->size);
 
     peerProxy->inputState = READING_BYTES;
     if (bufferPrepareForRead(peerProxy->inputBuffer, header->size) == -1) {