diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 374142702b..854752069e 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -1018,8 +1018,8 @@ bool QProcessPrivate::tryReadFromChannel(Channel *channel)
         return false;
     }
 #if defined QPROCESS_DEBUG
-    qDebug("QProcessPrivate::tryReadFromChannel(%d), read %d bytes from the process' output",
-           int(channel - &stdinChannel), int(readBytes));
+    qDebug("QProcessPrivate::tryReadFromChannel(%d), read %lld bytes from the process' output",
+           int(channel - &stdinChannel), readBytes);
 #endif
 
     if (channel->closed) {
diff --git a/src/corelib/io/qprocess_win.cpp b/src/corelib/io/qprocess_win.cpp
index 1527cf93ed..148c6378c6 100644
--- a/src/corelib/io/qprocess_win.cpp
+++ b/src/corelib/io/qprocess_win.cpp
@@ -620,7 +620,8 @@ qint64 QProcessPrivate::bytesAvailableInChannel(const Channel *channel) const
 
     DWORD bytesAvail = channel->reader->bytesAvailable();
 #if defined QPROCESS_DEBUG
-    qDebug("QProcessPrivate::bytesAvailableInChannel(%d) == %d", channel - &stdinChannel, bytesAvail);
+    qDebug("QProcessPrivate::bytesAvailableInChannel(%d) == %lld",
+           int(channel - &stdinChannel), qint64(bytesAvail));
 #endif
     return bytesAvail;
 }