diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index e136c35a2..fccac85a4 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2055,11 +2055,12 @@ int mbedtls_ssl_tls13_fetch_handshake_msg(mbedtls_ssl_context *ssl,
  * \param[in] ssl  SSL context
  * \param[in] buf  Address of the first byte of the extensions vector.
  * \param[in] end  End of the buffer containing the list of extensions.
- * \param[out] extension_data  If the extension is present, address of its first
- *                             byte of data, NULL otherwise.
- * \param[out] extension_data_end  If the extension is present, address of the
- *                                 first byte immediately following the extension
- *                                 data, NULL otherwise.
+ * \param[out] supported_versions_data  If the extension is present, address of
+ *                                      its first byte of data, NULL otherwise.
+ * \param[out] supported_versions_data_end  If the extension is present, address
+ *                                          of the first byte immediately
+ *                                          following the extension data, NULL
+ *                                          otherwise.
  * \return 0  if the list of extensions does not contain a supported_versions
  *            extension.
  * \return 1  if the list of extensions contains a supported_versions
@@ -2071,8 +2072,8 @@ MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
     mbedtls_ssl_context *ssl,
     const unsigned char *buf, const unsigned char *end,
-    const unsigned char **extension_data,
-    const unsigned char **extension_data_end);
+    const unsigned char **supported_versions_data,
+    const unsigned char **supported_versions_data_end);
 
 /*
  * Handler of TLS 1.3 server certificate message
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 6cf47fe29..58d66cde8 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1324,8 +1324,8 @@ static int ssl_tls13_is_supported_versions_ext_present(
 {
     const unsigned char *p = buf;
     size_t legacy_session_id_echo_len;
-    const unsigned char *supported_versions_ext;
-    const unsigned char *supported_versions_ext_end;
+    const unsigned char *supported_versions_data;
+    const unsigned char *supported_versions_data_end;
 
     /*
      * Check there is enough data to access the legacy_session_id_echo vector
@@ -1349,7 +1349,7 @@ static int ssl_tls13_is_supported_versions_ext_present(
 
     return mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
         ssl, p, end,
-        &supported_versions_ext, &supported_versions_ext_end);
+        &supported_versions_data, &supported_versions_data_end);
 }
 
 /* Returns a negative value on failure, and otherwise
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 1a10e7563..d2082a7f1 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -89,15 +89,15 @@ cleanup:
 int mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
     mbedtls_ssl_context *ssl,
     const unsigned char *buf, const unsigned char *end,
-    const unsigned char **extension_data,
-    const unsigned char **extension_data_end)
+    const unsigned char **supported_versions_data,
+    const unsigned char **supported_versions_data_end)
 {
     const unsigned char *p = buf;
     size_t extensions_len;
     const unsigned char *extensions_end;
 
-    *extension_data = NULL;
-    *extension_data_end = NULL;
+    *supported_versions_data = NULL;
+    *supported_versions_data_end = NULL;
 
     /* Case of no extension */
     if (p == end) {
@@ -131,8 +131,8 @@ int mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
         MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, extension_data_len);
 
         if (extension_type == MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS) {
-            *extension_data = p;
-            *extension_data_end = p + extension_data_len;
+            *supported_versions_data = p;
+            *supported_versions_data_end = p + extension_data_len;
             return 1;
         }
         p += extension_data_len;
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index dbd9a52b3..f59f379d3 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1255,8 +1255,8 @@ static int ssl_tls13_parse_client_hello(mbedtls_ssl_context *ssl,
     const unsigned char *cipher_suites_end;
     size_t extensions_len;
     const unsigned char *extensions_end;
-    const unsigned char *supported_versions_ext;
-    const unsigned char *supported_versions_ext_end;
+    const unsigned char *supported_versions_data;
+    const unsigned char *supported_versions_data_end;
     mbedtls_ssl_handshake_params *handshake = ssl->handshake;
     int hrr_required = 0;
 
@@ -1360,7 +1360,7 @@ static int ssl_tls13_parse_client_hello(mbedtls_ssl_context *ssl,
      */
     ret = mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
         ssl, p + 2, end,
-        &supported_versions_ext, &supported_versions_ext_end);
+        &supported_versions_data, &supported_versions_data_end);
     if (ret < 0) {
         MBEDTLS_SSL_DEBUG_RET(1,
                               ("mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts"), ret);
@@ -1373,8 +1373,8 @@ static int ssl_tls13_parse_client_hello(mbedtls_ssl_context *ssl,
 
     if (ret == 1) {
         ret = ssl_tls13_parse_supported_versions_ext(ssl,
-                                                     supported_versions_ext,
-                                                     supported_versions_ext_end);
+                                                     supported_versions_data,
+                                                     supported_versions_data_end);
         if (ret < 0) {
             MBEDTLS_SSL_DEBUG_RET(1,
                                   ("ssl_tls13_parse_supported_versions_ext"), ret);