diff --git a/mpm.c b/mpm.c
index 6408134..fbe7a73 100644
--- a/mpm.c
+++ b/mpm.c
@@ -682,14 +682,16 @@ static int mpm_open(struct multiboot *mboot)
     /* wait for watchdog and startup time */
     usleep(100000);
 
-    char version[16];
-    if (mpm_read_version(mpm, (uint8_t *)version, sizeof(version)))
+    char version[16 +1];
+    if (mpm_read_version(mpm, (uint8_t *)version, sizeof(version) -1))
     {
         fprintf(stderr, "failed to get bootloader version\n");
         mpm_close(mboot);
         return -1;
     }
 
+    version[16] = '\0';
+
     uint8_t chipinfo[8];
     if (mpm_read_chipinfo(mpm, chipinfo, sizeof(chipinfo)))
     {
diff --git a/twi.c b/twi.c
index 48f0755..2abd070 100644
--- a/twi.c
+++ b/twi.c
@@ -310,8 +310,8 @@ static int twi_open(struct multiboot *mboot)
     /* wait for watchdog and startup time */
     usleep(100000);
 
-    char version[16];
-    if (twi_read_version(twi, version, sizeof(version)))
+    char version[16 +1];
+    if (twi_read_version(twi, version, sizeof(version) -1))
     {
         fprintf(stderr, "failed to get bootloader version: %s\n",
                 strerror(errno));
@@ -320,6 +320,8 @@ static int twi_open(struct multiboot *mboot)
         return -1;
     }
 
+    version[16] = '\0';
+
     uint8_t chipinfo[8];
     if (twi_read_memory(twi, chipinfo, sizeof(chipinfo), MEMTYPE_CHIPINFO, 0x0000))
     {