diff --git a/docs/libcurl/symbols-in-versions b/docs/libcurl/symbols-in-versions
index e24b9619cd..ed2b010e94 100644
--- a/docs/libcurl/symbols-in-versions
+++ b/docs/libcurl/symbols-in-versions
@@ -607,7 +607,7 @@ CURLOPT_DOH_SSL_VERIFYPEER      7.76.0
 CURLOPT_DOH_SSL_VERIFYSTATUS    7.76.0
 CURLOPT_DOH_URL                 7.62.0
 CURLOPT_EGDSOCKET               7.7
-CURLOPT_ENCODING                7.10
+CURLOPT_ENCODING                7.10          7.21.6
 CURLOPT_ERRORBUFFER             7.1
 CURLOPT_EXPECT_100_TIMEOUT_MS   7.36.0
 CURLOPT_FAILONERROR             7.1