diff --git a/map.c b/map.c
index 2342c9e..360c889 100644
--- a/map.c
+++ b/map.c
@@ -10,11 +10,6 @@
 #include "bseq.h"
 #include "khash.h"
 
-struct mm_tbuf_s {
-	void *km;
-	int rep_len, frag_gap;
-};
-
 mm_tbuf_t *mm_tbuf_init(void)
 {
 	mm_tbuf_t *b;
diff --git a/minimap.h b/minimap.h
index 4ea81df..ee7b613 100644
--- a/minimap.h
+++ b/minimap.h
@@ -193,6 +193,11 @@ typedef struct {
 } mm_idx_reader_t;
 
 // memory buffer for thread-local storage during mapping
+struct mm_tbuf_s {
+	void *km;
+	int rep_len, frag_gap;
+};
+
 typedef struct mm_tbuf_s mm_tbuf_t;
 
 // global variables