diff --git a/src/jpegxl.imageio/jxlinput.cpp b/src/jpegxl.imageio/jxlinput.cpp
index 88f2ccea06..a734d70f71 100644
--- a/src/jpegxl.imageio/jxlinput.cpp
+++ b/src/jpegxl.imageio/jxlinput.cpp
@@ -360,6 +360,10 @@ JxlInput::open(const std::string& name, ImageSpec& newspec)
 
     m_spec = ImageSpec(info.xsize, info.ysize, m_channels, m_data_type);
 
+    if (!check_open(m_spec,
+                    { 0, (1 << 30) - 1, 0, (1 << 30) - 1, 0, 1, 0, 4099 }))
+        return false;
+
     // Read ICC profile
     if (m_icc_profile.size() && m_icc_profile.data()) {
         m_spec.attribute("ICCProfile",
diff --git a/src/webp.imageio/webpinput.cpp b/src/webp.imageio/webpinput.cpp
index 1277a2f3a7..86eb80f55c 100644
--- a/src/webp.imageio/webpinput.cpp
+++ b/src/webp.imageio/webpinput.cpp
@@ -233,6 +233,9 @@ WebpInput::open(const std::string& name, ImageSpec& spec,
             m_spec.attribute("oiio:UnassociatedAlpha", 1);
     }
 
+    if (!check_open(m_spec, { 0, (1 << 14) - 1, 0, (1 << 14) - 1, 0, 1, 0, 4 }))
+        return false;
+
     seek_subimage(0, 0);
     spec = m_spec;
     return true;