diff --git a/tools/ld-analyse/tbcsource.cpp b/tools/ld-analyse/tbcsource.cpp
index 333464fcd..c5cb9b88b 100644
--- a/tools/ld-analyse/tbcsource.cpp
+++ b/tools/ld-analyse/tbcsource.cpp
@@ -959,7 +959,7 @@ QImage TbcSource::generateQImage()
                 fieldHeight = inputHeight - 1;
             }
 
-            for (auto y = startingY; y < inputHeight; y++) {
+            for (auto y = startingY; y < fieldHeight; y++) {
                 auto *outputLine = reinterpret_cast<QRgb*>(outputImage.scanLine(y + inputOffset));
                 std::copy_n(&rgbData[fieldY * inputWidth], inputWidth, &outputLine[outputOffset]);