diff --git a/src/imageformats/tga.cpp b/src/imageformats/tga.cpp
index 13ea277..f08a346 100644
--- a/src/imageformats/tga.cpp
+++ b/src/imageformats/tga.cpp
@@ -145,6 +145,9 @@ struct TgaHeaderInfo {
         switch (tga.image_type) {
         case TGA_TYPE_RLE_INDEXED:
             rle = true;
+#if QT_VERSION >= QT_VERSION_CHECK(5,8,0)
+        Q_FALLTHROUGH();
+#endif
         // no break is intended!
         case TGA_TYPE_INDEXED:
             pal = true;
@@ -152,6 +155,9 @@ struct TgaHeaderInfo {
 
         case TGA_TYPE_RLE_RGB:
             rle = true;
+#if QT_VERSION >= QT_VERSION_CHECK(5,8,0)
+        Q_FALLTHROUGH();
+#endif
         // no break is intended!
         case TGA_TYPE_RGB:
             rgb = true;
@@ -159,6 +165,9 @@ struct TgaHeaderInfo {
 
         case TGA_TYPE_RLE_GREY:
             rle = true;
+#if QT_VERSION >= QT_VERSION_CHECK(5,8,0)
+        Q_FALLTHROUGH();
+#endif
         // no break is intended!
         case TGA_TYPE_GREY:
             grey = true;
diff --git a/src/imageformats/xcf.cpp b/src/imageformats/xcf.cpp
index d0eccc4..7759114 100644
--- a/src/imageformats/xcf.cpp
+++ b/src/imageformats/xcf.cpp
@@ -1323,7 +1323,9 @@ bool XCFImageFormat::initializeImage(XCFImage &xcf_image)
             image.fill(qRgb(255, 255, 255));
             break;
         } // else, fall through to 32-bit representation
-
+#if QT_VERSION >= QT_VERSION_CHECK(5,8,0)
+        Q_FALLTHROUGH();
+#endif
     case RGBA_GIMAGE:
         image = QImage(xcf_image.width, xcf_image.height, QImage::Format_ARGB32);
         if (image.isNull()) {
@@ -1343,7 +1345,9 @@ bool XCFImageFormat::initializeImage(XCFImage &xcf_image)
             image.fill(255);
             break;
         } // else, fall through to 32-bit representation
-
+#if QT_VERSION >= QT_VERSION_CHECK(5,8,0)
+        Q_FALLTHROUGH();
+#endif
     case GRAYA_GIMAGE:
         image = QImage(xcf_image.width, xcf_image.height, QImage::Format_ARGB32);
         if (image.isNull()) {