diff --git a/src/codec_aom.c b/src/codec_aom.c
index 175f9c524e..55f1d0e34d 100644
--- a/src/codec_aom.c
+++ b/src/codec_aom.c
@@ -1091,6 +1091,7 @@ static avifResult aomCodecEncodeImage(avifCodec * codec,
                 size_t monoUVSize = (size_t)monoUVHeight * monoUVRowBytes;
 
                 monoUVPlane = avifAlloc(monoUVSize);
+                AVIF_CHECKERR(monoUVPlane != NULL, AVIF_RESULT_OUT_OF_MEMORY); // No need for aom_img_free() because !aomImageAllocated
                 aomImage.planes[1] = monoUVPlane;
                 aomImage.stride[1] = monoUVRowBytes;
             }