diff --git a/src/_webp.c b/src/_webp.c
index a1b4dbc1a..4e7d41f11 100644
--- a/src/_webp.c
+++ b/src/_webp.c
@@ -450,12 +450,16 @@ _anim_decoder_get_next(PyObject *self) {
     int timestamp;
     PyObject *bytes;
     PyObject *ret;
+    ImagingSectionCookie cookie;
     WebPAnimDecoderObject *decp = (WebPAnimDecoderObject *)self;
 
+    ImagingSectionEnter(&cookie);
     if (!WebPAnimDecoderGetNext(decp->dec, &buf, &timestamp)) {
+        ImagingSectionLeave(&cookie);
         PyErr_SetString(PyExc_OSError, "failed to read next frame");
         return NULL;
     }
+    ImagingSectionLeave(&cookie);
 
     bytes = PyBytes_FromStringAndSize(
         (char *)buf, decp->info.canvas_width * 4 * decp->info.canvas_height);