diff --git a/moo/moolua/lua/ldo.c b/moo/moolua/lua/ldo.c
index e8a91a58..97961907 100644
--- a/moo/moolua/lua/ldo.c
+++ b/moo/moolua/lua/ldo.c
@@ -108,6 +108,15 @@ L_GNUC_NORETURN void luaD_throw (lua_State *L, int errcode) {
 }
 
 
+int luaD_inerror (lua_State *L)
+{
+  if (L->errorJmp)
+    return L->errorJmp->status != 0;
+  else
+    return 0;
+}
+
+
 int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
   struct lua_longjmp lj;
   lj.status = 0;
diff --git a/moo/moolua/lua/ldo.h b/moo/moolua/lua/ldo.h
index 98fddac5..a9fdd914 100644
--- a/moo/moolua/lua/ldo.h
+++ b/moo/moolua/lua/ldo.h
@@ -53,5 +53,7 @@ LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
 
 LUAI_FUNC void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop);
 
+int luaD_inerror (lua_State *L);
+
 #endif