diff --git a/rust/src/applayer.rs b/rust/src/applayer.rs
index 1a9a696d46..d5700268fe 100644
--- a/rust/src/applayer.rs
+++ b/rust/src/applayer.rs
@@ -377,6 +377,7 @@ extern {
                                                      pp_min_depth: u16, pp_max_depth: u16) -> c_int;
     pub fn AppLayerProtoDetectConfProtoDetectionEnabled(ipproto: *const c_char, proto: *const c_char) -> c_int;
     pub fn AppLayerProtoDetectConfProtoDetectionEnabledDefault(ipproto: *const c_char, proto: *const c_char, default: bool) -> c_int;
+    pub fn AppLayerRequestProtocolTLSUpgrade(flow: *const Flow);
 }
 
 // Defined in app-layer-parser.h