diff --git a/compiler/wasmbase.pas b/compiler/wasmbase.pas
index d739c89c70..55b9b29271 100644
--- a/compiler/wasmbase.pas
+++ b/compiler/wasmbase.pas
@@ -105,6 +105,7 @@ const
   WASM_SYM_EXPORTED          = $20;
   WASM_SYM_EXPLICIT_NAME     = $40;
   WASM_SYM_NO_STRIP          = $80;
+  WASM_SYM_TLS               = $100;
 
 implementation