diff --git a/library/asn1write.c b/library/asn1write.c
index fb72574..40584d6 100644
--- a/library/asn1write.c
+++ b/library/asn1write.c
@@ -75,7 +75,7 @@
     return 1;
 }
 
-static int mbedtls_write_len_and_tag(unsigned char **p,
+static int mbedtls_asn1_write_len_and_tag(unsigned char **p,
                                      const unsigned char *start,
                                      size_t len,
                                      unsigned char tag)
@@ -139,7 +139,7 @@
         len += 1;
     }
 
-    ret = mbedtls_write_len_and_tag(p, start, len, MBEDTLS_ASN1_INTEGER);
+    ret = mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_INTEGER);
 
 cleanup:
     return ret;
@@ -150,7 +150,7 @@
 {
     // Write NULL
     //
-    return mbedtls_write_len_and_tag(p, start, 0, MBEDTLS_ASN1_NULL);
+    return mbedtls_asn1_write_len_and_tag(p, start, 0, MBEDTLS_ASN1_NULL);
 }
 
 int mbedtls_asn1_write_oid(unsigned char **p, const unsigned char *start,
@@ -161,7 +161,7 @@
 
     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
                                                             (const unsigned char *) oid, oid_len));
-    return mbedtls_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OID);
+    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OID);
 }
 
 int mbedtls_asn1_write_algorithm_identifier(unsigned char **p, const unsigned char *start,
@@ -188,7 +188,7 @@
 
     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
 
-    return mbedtls_write_len_and_tag(p, start, len,
+    return mbedtls_asn1_write_len_and_tag(p, start, len,
                                      MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE);
 }
 
@@ -203,7 +203,7 @@
     *--(*p) = (boolean) ? 255 : 0;
     len++;
 
-    return mbedtls_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BOOLEAN);
+    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BOOLEAN);
 }
 
 static int asn1_write_tagged_int(unsigned char **p, const unsigned char *start, int val, int tag)
@@ -227,7 +227,7 @@
         len += 1;
     }
 
-    return mbedtls_write_len_and_tag(p, start, len, tag);
+    return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
 }
 
 int mbedtls_asn1_write_int(unsigned char **p, const unsigned char *start, int val)
@@ -250,7 +250,7 @@
                                                             (const unsigned char *) text,
                                                             text_len));
 
-    return mbedtls_write_len_and_tag(p, start, len, tag);
+    return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
 }
 
 int mbedtls_asn1_write_utf8_string(unsigned char **p, const unsigned char *start,
@@ -342,7 +342,7 @@
     /* Write unused bits */
     *--(*p) = (unsigned char) unused_bits;
 
-    return mbedtls_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BIT_STRING);
+    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BIT_STRING);
 }
 
 int mbedtls_asn1_write_octet_string(unsigned char **p, const unsigned char *start,
@@ -353,7 +353,7 @@
 
     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, buf, size));
 
-    return mbedtls_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OCTET_STRING);
+    return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OCTET_STRING);
 }