diff --git a/library/x509_crt.c b/library/x509_crt.c
index 42f1fc2..755ca60 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1785,6 +1785,7 @@
                                        const char *prefix )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t i;
     size_t n = *size;
     char *p = *buf;
     const mbedtls_x509_sequence *cur = subject_alt_name;
@@ -1837,18 +1838,11 @@
                     ret = mbedtls_snprintf( p, n, "\n%s            hardware serial number : ", prefix );
                     MBEDTLS_X509_SAFE_SNPRINTF;
 
-                    if( other_name->value.hardware_module_name.val.len >= n )
+                    for( i = 0; i < other_name->value.hardware_module_name.val.len; i++ )
                     {
-                        *p = '\0';
-                        return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
+                        ret = mbedtls_snprintf( p, n, "%02X", other_name->value.hardware_module_name.val.p[i] );
+                        MBEDTLS_X509_SAFE_SNPRINTF;
                     }
-
-                    memcpy( p, other_name->value.hardware_module_name.val.p,
-                            other_name->value.hardware_module_name.val.len );
-                    p += other_name->value.hardware_module_name.val.len;
-
-                    n -= other_name->value.hardware_module_name.val.len;
-
                 }/* MBEDTLS_OID_ON_HW_MODULE_NAME */
             }
             break;