diff --git a/firmware/application/apps/ui_ss_viewer.cpp b/firmware/application/apps/ui_ss_viewer.cpp
index 4cb41c429..67ead2955 100644
--- a/firmware/application/apps/ui_ss_viewer.cpp
+++ b/firmware/application/apps/ui_ss_viewer.cpp
@@ -58,7 +58,7 @@ void ScreenshotViewer::paint(Painter& painter) {
     }
 
     // Screenshots from PNGWriter are all this size.
-    if (file.size() != 232383) {
+    if ((file.size() != 232383 && screen_width == 240) || (screen_width == 320 && file.size() != 463743)) {
         show_invalid();
         return;
     }
diff --git a/firmware/common/png_writer.cpp b/firmware/common/png_writer.cpp
index 3251bad4b..581720586 100644
--- a/firmware/common/png_writer.cpp
+++ b/firmware/common/png_writer.cpp
@@ -80,7 +80,8 @@ Optional<File::Error> PNGWriter::create(
     png_ihdr_dyn[14] = (height >> 8) & 0xFF;
     png_ihdr_dyn[15] = height & 0xFF;
     crc.reset();
-    crc.process_bytes(png_ihdr_dyn.data(), 25);
+    crc.process_bytes(&png_ihdr_dyn[4], 4);   // Process chunk type "IHDR"
+    crc.process_bytes(&png_ihdr_dyn[8], 13);  // Process chunk data
     uint32_t crci = crc.checksum();
 
     png_ihdr_dyn[21] = (crci >> 24) & 0xFF;