diff --git a/lib/jxl/fields_test.cc b/lib/jxl/fields_test.cc
index 50e3ac22122..c11b0523019 100644
--- a/lib/jxl/fields_test.cc
+++ b/lib/jxl/fields_test.cc
@@ -228,7 +228,7 @@ TEST(FieldsTest, TestRoundtripSize) {
 // Ensure all values can be reached by the encoding.
 TEST(FieldsTest, TestCropRect) {
   CodecMetadata metadata;
-  for (int32_t i = -1000; i < 19000; ++i) {
+  for (int32_t i = -999; i < 19000; ++i) {
     FrameHeader f(&metadata);
     f.custom_size_or_origin = true;
     f.frame_origin.x0 = i;
diff --git a/lib/jxl/frame_header.cc b/lib/jxl/frame_header.cc
index b08c351e81f..c2f6b26ae34 100644
--- a/lib/jxl/frame_header.cc
+++ b/lib/jxl/frame_header.cc
@@ -271,6 +271,11 @@ Status FrameHeader::VisitFields(Visitor* JXL_RESTRICT visitor) {
       // Frame size
       JXL_QUIET_RETURN_IF_ERROR(visitor->U32(enc, 0, &frame_size.xsize));
       JXL_QUIET_RETURN_IF_ERROR(visitor->U32(enc, 0, &frame_size.ysize));
+      if (custom_size_or_origin &&
+          (frame_size.xsize == 0 || frame_size.ysize == 0)) {
+        return JXL_FAILURE(
+            "Invalid crop dimensions for frame: zero width or height");
+      }
       int32_t image_xsize = default_xsize();
       int32_t image_ysize = default_ysize();
       if (frame_type == FrameType::kRegularFrame ||