diff --git a/src/imageformats/jxr.cpp b/src/imageformats/jxr.cpp
index fbc2bcf..7e535f1 100644
--- a/src/imageformats/jxr.cpp
+++ b/src/imageformats/jxr.cpp
@@ -977,9 +977,9 @@ bool JXRHandler::read(QImage *outImage)
                 return false;
             }
         } else { // additional buffer needed
-            qint64 convStrideSize = (img.width() * d->pDecoder->WMP.wmiI.cBitsPerUnit + 7) / 8;
-            qint64 buffSize = convStrideSize * img.height();
-            qint64 limit = QImageReader::allocationLimit();
+            qsizetype convStrideSize = (img.width() * d->pDecoder->WMP.wmiI.cBitsPerUnit + 7) / 8;
+            qsizetype buffSize = convStrideSize * img.height();
+            qsizetype limit = QImageReader::allocationLimit();
             if (limit && (buffSize + img.sizeInBytes()) > limit * 1024 * 1024) {
                 qCWarning(LOG_JXRPLUGIN) << "JXRHandler::read() unable to covert due to allocation limit set:" << limit << "MiB";
                 return false;