diff --git a/compress/function/zstd.c b/compress/function/zstd.c
index 5614b9e..8352b6f 100644
--- a/compress/function/zstd.c
+++ b/compress/function/zstd.c
@@ -279,6 +279,7 @@ static enum b_status decompress(struct b_compressor *compressor)
 
 const struct b_compression_function z__b_compression_function_zstd = {
 	.f_name = "zstd",
+	.f_ctx_size = sizeof(struct zstd_ctx),
 	.f_buffer_size = buffer_size,
 	.f_init = init,
 	.f_fini = fini,