diff --git a/include/cubescript/cubescript.hh b/include/cubescript/cubescript.hh
index a31d67a..f5430d3 100644
--- a/include/cubescript/cubescript.hh
+++ b/include/cubescript/cubescript.hh
@@ -339,7 +339,7 @@ private:
 };
 
 using CsHookCb = ostd::Function<void()>;
-using CsPanicCb = ostd::Function<void(CsString, CsStackState)>;
+using CsPanicCb = ostd::Function<void(ostd::ConstCharRange, CsStackState)>;
 
 struct OSTD_EXPORT CsState {
     CsMap<ostd::ConstCharRange, CsIdent *> idents;
diff --git a/src/cubescript.cc b/src/cubescript.cc
index c34762f..42209a4 100644
--- a/src/cubescript.cc
+++ b/src/cubescript.cc
@@ -261,7 +261,7 @@ CsState::CsState():
     noalias.argstack = nullptr;
 
     /* default panic func */
-    p_panicfunc = [this](CsString v, CsStackState) {
+    p_panicfunc = [this](ostd::ConstCharRange v, CsStackState) {
         get_err().writefln(
             "PANIC: unprotected error in call to CubeScript (%s)", v
         );