diff --git a/src/proto_http.c b/src/proto_http.c
index 0ed2acb69..e6dd041bf 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -449,7 +449,7 @@ const char http_is_ver_token[256] = {
 	['.'] = 1, ['/'] = 1,
 	['0'] = 1, ['1'] = 1, ['2'] = 1, ['3'] = 1, ['4'] = 1,
 	['5'] = 1, ['6'] = 1, ['7'] = 1, ['8'] = 1, ['9'] = 1,
-	['H'] = 1, ['P'] = 1, ['T'] = 1,
+	['H'] = 1, ['P'] = 1, ['R'] = 1, ['S'] = 1, ['T'] = 1,
 };