diff --git a/CHANGES.md b/CHANGES.md
index f158154..976154a 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,9 @@
 # CHANGES
 
+## 1.13.8
+
+* Use gzputs instead of gzprintf when writing reference contig lines to avoid buffer overflow
+
 ## 1.13.7
 
 * Modify means by which zlib version is detected.
diff --git a/Makefile b/Makefile
index 3dfc138..66e8ed3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-CAVEMAN_VERSION=1.13.7
+CAVEMAN_VERSION=1.13.8
 TEST_REF?=""
 #Compiler
 CC?=gcc
diff --git a/src/output.c b/src/output.c
index bb18bed..31e6ba6 100644
--- a/src/output.c
+++ b/src/output.c
@@ -298,7 +298,7 @@ int output_vcf_header(gzFile out, char *tum_bam, char *norm_bam, char *ref_seq_l
 	//Add reference sequence headers
 	contigs = output_generate_reference_contig_lines(tum_bam, assembly, species);
 	check(contigs != NULL,"Error fetching contigs from bam file.");
-	write = gzprintf(out,"%s",contigs);
+	write = gzputs(out,contigs);
 	check(write==sizeof(char)*strlen(contigs),"Error (%d) writing contigs.",write);
 
 	//INFO lines