diff --git a/bwa.c b/bwa.c
index 30e5284..80a4b8f 100644
--- a/bwa.c
+++ b/bwa.c
@@ -14,6 +14,7 @@
 
 int bwa_verbose = 3;
 char bwa_rg_id[256];
+char *bwa_pg;
 
 /************************
  * Batch FASTA/Q reader *
@@ -352,7 +353,7 @@ void bwa_print_sam_hdr(const bntseq_t *bns, const char *rg_line)
 	for (i = 0; i < bns->n_seqs; ++i)
 		err_printf("@SQ\tSN:%s\tLN:%d\n", bns->anns[i].name, bns->anns[i].len);
 	if (rg_line) err_printf("%s\n", rg_line);
-	err_printf("%s\n", bwa_pg);
+	if (bwa_pg) err_printf("%s\n", bwa_pg);
 }
 
 static char *bwa_escape(char *s)
diff --git a/example.c b/example.c
index a6c9bdd..96f25be 100644
--- a/example.c
+++ b/example.c
@@ -47,10 +47,10 @@ int main(int argc, char *argv[])
 			if (ar.a[i].secondary >= 0) continue; // skip secondary alignments
 			a = mem_reg2aln(opt, idx->bns, idx->pac, ks->seq.l, ks->seq.s, &ar.a[i]); // get forward-strand position and CIGAR
 			// print alignment
-			err_printf("%s\t%c\t%s\t%ld\t%d\t", ks->name.s, "+-"[a.is_rev], idx->bns->anns[a.rid].name, (long)a.pos, a.mapq);
+			printf("%s\t%c\t%s\t%ld\t%d\t", ks->name.s, "+-"[a.is_rev], idx->bns->anns[a.rid].name, (long)a.pos, a.mapq);
 			for (k = 0; k < a.n_cigar; ++k) // print CIGAR
-				err_printf("%d%c", a.cigar[k]>>4, "MIDSH"[a.cigar[k]&0xf]);
-			err_printf("\t%d\n", a.NM); // print edit distance
+				printf("%d%c", a.cigar[k]>>4, "MIDSH"[a.cigar[k]&0xf]);
+			printf("\t%d\n", a.NM); // print edit distance
 			free(a.cigar); // don't forget to deallocate CIGAR
 		}
 		free(ar.a); // and deallocate the hit list
@@ -58,7 +58,7 @@ int main(int argc, char *argv[])
 
 	free(opt);
 	kseq_destroy(ks);
-	err_gzclose(fp);
+	gzclose(fp);
 	bwa_idx_destroy(idx);
 	return 0;
 }
diff --git a/main.c b/main.c
index e0f0edb..1a18559 100644
--- a/main.c
+++ b/main.c
@@ -4,7 +4,7 @@
 #include "utils.h"
 
 #ifndef PACKAGE_VERSION
-#define PACKAGE_VERSION "0.7.10-r912-dirty"
+#define PACKAGE_VERSION "0.7.10-r915-dirty"
 #endif
 
 int bwa_fa2pac(int argc, char *argv[]);
@@ -26,8 +26,6 @@ int main_shm(int argc, char *argv[]);
 
 int main_pemerge(int argc, char *argv[]);
 	
-char *bwa_pg;
-
 static int usage()
 {
 	fprintf(stderr, "\n");
@@ -61,6 +59,7 @@ static int usage()
 
 int main(int argc, char *argv[])
 {
+	extern char *bwa_pg;
 	int i, ret;
 	double t_real;
 	kstring_t pg = {0,0,0};