diff --git a/src/backend/access/common/toast_compression.c b/src/backend/access/common/toast_compression.c
index 00af1740cf..74e449992a 100644
--- a/src/backend/access/common/toast_compression.c
+++ b/src/backend/access/common/toast_compression.c
@@ -220,6 +220,10 @@ lz4_decompress_datum_slice(const struct varlena *value, int32 slicelength)
 	if (LZ4_versionNumber() < 10803)
 		return lz4_decompress_datum(value);
 
+	/* liblz4 assumes that slicelength is not an overestimate */
+	if (slicelength >= VARRAWSIZE_4B_C(value))
+		return lz4_decompress_datum(value);
+
 	/* allocate memory for the uncompressed data */
 	result = (struct varlena *) palloc(slicelength + VARHDRSZ);