diff --git a/bseq.c b/bseq.c
index db79299..6bf55f5 100644
--- a/bseq.c
+++ b/bseq.c
@@ -54,15 +54,23 @@ void mm_bseq_close(mm_bseq_file_t *fp)
 	free(fp);
 }
 
+static inline char *kstrdup(const kstring_t *s)
+{
+	char *t;
+	t = (char*)malloc(s->l + 1);
+	memcpy(t, s->s, s->l + 1);
+	return t;
+}
+
 static inline void kseq2bseq(kseq_t *ks, mm_bseq1_t *s, int with_qual)
 {
 	int i;
-	s->name = strdup(ks->name.s);
-	s->seq = strdup(ks->seq.s);
+	s->name = kstrdup(&ks->name);
+	s->seq = kstrdup(&ks->seq);
 	for (i = 0; i < ks->seq.l; ++i) // convert U to T
 		if (s->seq[i] == 'u' || s->seq[i] == 'U')
 			--s->seq[i];
-	s->qual = with_qual && ks->qual.l? strdup(ks->qual.s) : 0;
+	s->qual = with_qual && ks->qual.l? kstrdup(&ks->qual) : 0;
 	s->l_seq = ks->seq.l;
 }
 
diff --git a/main.c b/main.c
index 9fb8115..da7931b 100644
--- a/main.c
+++ b/main.c
@@ -6,7 +6,7 @@
 #include "mmpriv.h"
 #include "getopt.h"
 
-#define MM_VERSION "2.8-r703-dirty"
+#define MM_VERSION "2.8-r706-dirty"
 
 #ifdef __linux__
 #include <sys/resource.h>