diff --git a/bgzf.c b/bgzf.c
index 3bea718..9833414 100644
--- a/bgzf.c
+++ b/bgzf.c
@@ -104,8 +104,8 @@ static BGZF *bgzf_read_init()
 	BGZF *fp;
 	fp = calloc(1, sizeof(BGZF));
 	fp->open_mode = 'r';
-	fp->uncompressed_block = malloc(BGZF_BLOCK_SIZE);
-	fp->compressed_block = malloc(BGZF_BLOCK_SIZE);
+	fp->uncompressed_block = malloc(BGZF_MAX_BLOCK_SIZE);
+	fp->compressed_block = malloc(BGZF_MAX_BLOCK_SIZE);
 #ifdef BGZF_CACHE
 	fp->cache = kh_init(cache);
 #endif
@@ -117,8 +117,8 @@ static BGZF *bgzf_write_init(int compress_level) // compress_level==-1 for the d
 	BGZF *fp;
 	fp = calloc(1, sizeof(BGZF));
 	fp->open_mode = 'w';
-	fp->uncompressed_block = malloc(BGZF_BLOCK_SIZE);
-	fp->compressed_block = malloc(BGZF_BLOCK_SIZE);
+	fp->uncompressed_block = malloc(BGZF_MAX_BLOCK_SIZE);
+	fp->compressed_block = malloc(BGZF_MAX_BLOCK_SIZE);
 	fp->compress_level = compress_level < 0? Z_DEFAULT_COMPRESSION : compress_level; // Z_DEFAULT_COMPRESSION==-1
 	if (fp->compress_level > 9) fp->compress_level = Z_DEFAULT_COMPRESSION;
 	return fp;
diff --git a/bgzf.h b/bgzf.h
index 1fdf625..888df8c 100644
--- a/bgzf.h
+++ b/bgzf.h
@@ -32,7 +32,8 @@
 #include <stdio.h>
 #include <zlib.h>
 
-#define BGZF_BLOCK_SIZE 0x10000 // 64k
+#define BGZF_BLOCK_SIZE     0x10000
+#define BGZF_MAX_BLOCK_SIZE 0x10000
 
 #define BGZF_ERR_ZLIB   1
 #define BGZF_ERR_HEADER 2
@@ -71,7 +72,7 @@ extern "C" {
 	 * @param fd    file descriptor
 	 * @param mode  mode matching /[rwu0-9]+/: 'r' for reading, 'w' for writing and a digit specifies
 	 *              the zlib compression level; if both 'r' and 'w' are present, 'w' is ignored.
-     * @return      BGZF file handler; 0 on error
+	 * @return      BGZF file handler; 0 on error
 	 */
 	BGZF* bgzf_dopen(int fd, const char *mode);