diff --git a/reftable/block_test.c b/reftable/block_test.c
index 90aecd5a7c..de8f426a42 100644
--- a/reftable/block_test.c
+++ b/reftable/block_test.c
@@ -34,11 +34,12 @@ static void test_block_read_write(void)
 	struct block_reader br = { 0 };
 	struct block_iter it = BLOCK_ITER_INIT;
 	int j = 0;
+	struct strbuf block_data = STRBUF_INIT;
 	struct strbuf want = STRBUF_INIT;
 
 	REFTABLE_CALLOC_ARRAY(block.data, block_size);
 	block.len = block_size;
-	block.source = malloc_block_source();
+	block_source_from_strbuf(&block.source, &block_data);
 	block_writer_init(&bw, BLOCK_TYPE_REF, block.data, block_size,
 			  header_off, hash_size(GIT_SHA1_FORMAT_ID));
 
diff --git a/reftable/blocksource.c b/reftable/blocksource.c
index eeed254ba9..1774853011 100644
--- a/reftable/blocksource.c
+++ b/reftable/blocksource.c
@@ -55,26 +55,6 @@ void block_source_from_strbuf(struct reftable_block_source *bs,
 	bs->arg = buf;
 }
 
-static void malloc_return_block(void *b, struct reftable_block *dest)
-{
-	if (dest->len)
-		memset(dest->data, 0xff, dest->len);
-	reftable_free(dest->data);
-}
-
-static struct reftable_block_source_vtable malloc_vtable = {
-	.return_block = &malloc_return_block,
-};
-
-static struct reftable_block_source malloc_block_source_instance = {
-	.ops = &malloc_vtable,
-};
-
-struct reftable_block_source malloc_block_source(void)
-{
-	return malloc_block_source_instance;
-}
-
 struct file_block_source {
 	uint64_t size;
 	unsigned char *data;
diff --git a/reftable/blocksource.h b/reftable/blocksource.h
index 072e2727ad..659a27b406 100644
--- a/reftable/blocksource.h
+++ b/reftable/blocksource.h
@@ -17,6 +17,4 @@ struct reftable_block_source;
 void block_source_from_strbuf(struct reftable_block_source *bs,
 			      struct strbuf *buf);
 
-struct reftable_block_source malloc_block_source(void);
-
 #endif