diff --git a/src/tools/qmutex_unix.cpp b/src/tools/qmutex_unix.cpp
index de0f909..6934253 100644
--- a/src/tools/qmutex_unix.cpp
+++ b/src/tools/qmutex_unix.cpp
@@ -72,6 +72,7 @@ typedef pthread_mutex_t     Q_MUTEX_T;
 #include "qmutex_p.h"
 
 #include <errno.h>
+#include <stdint.h>
 #include <string.h>
 
 // Private class declarations
@@ -270,8 +271,8 @@ void QRecursiveMutexPrivate::unlock()
     } else {
 #ifdef QT_CHECK_RANGE
 	qWarning("QMutex::unlock: unlock from different thread than locker");
-	qWarning("                was locked by %d, unlock attempt from %d",
-		 (int)owner, (int)pthread_self());
+	qWarning("                was locked by %d, unlock attempt from %lu",
+		 (int)owner, (uintptr_t)pthread_self());
 #endif
     }