diff --git a/library/x509.c b/library/x509.c
index a3d7a18..fe4e3e3 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -849,7 +849,7 @@
                 ret = mbedtls_snprintf(p, n, ".%u", value);
             }
             if (ret < 2 || (size_t) ret >= n) {
-                return MBEDTLS_ERR_OID_BUF_TOO_SMALL;
+                return PSA_ERROR_BUFFER_TOO_SMALL;
             }
             n -= (size_t) ret;
             p += ret;
@@ -912,7 +912,7 @@
                 p += ret;
                 ret = mbedtls_snprintf(p, n, "=");
                 print_hexstring = 1;
-            } else if (ret == MBEDTLS_ERR_OID_BUF_TOO_SMALL) {
+            } else if (ret == PSA_ERROR_BUFFER_TOO_SMALL) {
                 return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
             } else {
                 ret = mbedtls_snprintf(p, n, "\?\?=");
diff --git a/library/x509_create.c b/library/x509_create.c
index 7ca5517..7621698 100644
--- a/library/x509_create.c
+++ b/library/x509_create.c
@@ -314,7 +314,7 @@
     size_t num_bytes = oid_subidentifier_num_bytes(value);
 
     if ((size_t) (bound - *p) < num_bytes) {
-        return MBEDTLS_ERR_OID_BUF_TOO_SMALL;
+        return PSA_ERROR_BUFFER_TOO_SMALL;
     }
     (*p)[num_bytes - 1] = (unsigned char) (value & 0x7f);
     value >>= 7;
diff --git a/library/x509_oid.h b/library/x509_oid.h
index 5b12677..46cfd54 100644
--- a/library/x509_oid.h
+++ b/library/x509_oid.h
@@ -21,8 +21,6 @@
 
 /** OID is not found. */
 #define MBEDTLS_ERR_OID_NOT_FOUND                         -0x002E
-/** output buffer is too small */
-#define MBEDTLS_ERR_OID_BUF_TOO_SMALL                     -0x000B
 
 /*
  * Maximum number of OID components allowed