diff --git a/src/cs_state.cc b/src/cs_state.cc
index c60f9df..2f352d1 100644
--- a/src/cs_state.cc
+++ b/src/cs_state.cc
@@ -794,11 +794,13 @@ static void do_run(
     std::uint32_t *cbuf = bcode_alloc(ts.istate, gs.code.size());
     std::memcpy(cbuf, gs.code.data(), gs.code.size() * sizeof(std::uint32_t));
     bcode_incr(cbuf);
-    call_with_cleanup([&ts, cbuf, &ret]() {
+    try {
         vm_exec(ts, cbuf + 1, ret);
-    }, [cbuf]() {
+    } catch (...) {
         bcode_decr(cbuf);
-    });
+        throw;
+    }
+    bcode_decr(cbuf);
 }
 
 LIBCUBESCRIPT_EXPORT void state::run(std::string_view code, any_value &ret) {
diff --git a/src/cs_std.hh b/src/cs_std.hh
index af1047b..1bfd124 100644
--- a/src/cs_std.hh
+++ b/src/cs_std.hh
@@ -13,21 +13,6 @@
 
 namespace cubescript {
 
-/* run func, call the second one after finishing */
-
-template<typename F1, typename F2>
-inline void call_with_cleanup(F1 &&dof, F2 &&clf) {
-    struct scope_exit {
-        scope_exit(std::decay_t<F2> &f): func(&f) {}
-        ~scope_exit() {
-            (*func)();
-        }
-        std::decay_t<F2> *func;
-    };
-    scope_exit cleanup(clf);
-    dof();
-}
-
 /* a value buffer */
 
 template<typename T>
diff --git a/src/cs_vm.cc b/src/cs_vm.cc
index 0d1fadc..991f0e1 100644
--- a/src/cs_vm.cc
+++ b/src/cs_vm.cc
@@ -224,9 +224,7 @@ void exec_alias(
         alias_impl *
     >(a)->compile_code(ts)->get_raw();
     bcode_incr(codep);
-    call_with_cleanup([&]() {
-        vm_exec(ts, codep+1, result);
-    }, [&]() {
+    auto cleanup = [&]() {
         bcode_decr(codep);
         ts.callstack = aliaslink.next;
         ts.pstate->identflags = oldflags;
@@ -247,7 +245,14 @@ void exec_alias(
         force_arg(result, op & BC_INST_RET_MASK);
         anargs->set_value(integer_type(oldargs));
         nargs = offset - skip;
-    });
+    };
+    try {
+        vm_exec(ts, codep + 1, result);
+    } catch (...) {
+        cleanup();
+        throw;
+    }
+    cleanup();
 }
 
 static constexpr int MaxRunDepth = 255;
@@ -520,14 +525,19 @@ std::uint32_t *vm_exec(
                         ts.idstack.emplace_back(*ts.pstate)
                     );
                 }
-                call_with_cleanup([&]() {
-                    code = vm_exec(ts, code, result);
-                }, [&]() {
+                auto cleanup = [&]() {
                     for (std::size_t i = offset; i < args.size(); ++i) {
                         pop_alias(args[i].get_ident());
                     }
                     ts.idstack.resize(idstsz, ident_stack{*ts.pstate});
-                });
+                };
+                try {
+                    code = vm_exec(ts, code, result);
+                } catch (...) {
+                    cleanup();
+                    throw;
+                }
+                cleanup();
                 return code;
             }
 
@@ -1138,14 +1148,19 @@ noid:
                                 ts.idstack.emplace_back(*ts.pstate)
                             );
                         }
-                        call_with_cleanup([&]() {
-                            code = vm_exec(ts, code, result);
-                        }, [&]() {
+                        auto cleanup = [&]() {
                             for (size_t j = 0; j < size_t(callargs); ++j) {
                                 pop_alias(args[offset + j].get_ident());
                             }
                             ts.idstack.resize(idstsz, ident_stack{*ts.pstate});
-                        });
+                        };
+                        try {
+                            code = vm_exec(ts, code, result);
+                        } catch (...) {
+                            cleanup();
+                            throw;
+                        }
+                        cleanup();
                         return code;
                     }
                     case ID_IVAR:
diff --git a/src/cs_vm.hh b/src/cs_vm.hh
index 559958d..e7f34e5 100644
--- a/src/cs_vm.hh
+++ b/src/cs_vm.hh
@@ -66,7 +66,7 @@ static void call_with_args(thread_state &ts, F body) {
         aliaslink.usedargs.set();
     }
     ts.callstack = &aliaslink;
-    call_with_cleanup(std::move(body), [&]() {
+    auto cleanup = [&]() {
         if (prevstack) {
             prevstack->usedargs = aliaslink.usedargs;
         }
@@ -81,7 +81,14 @@ static void call_with_args(thread_state &ts, F body) {
             mask2 >>= 1;
         }
         ts.idstack.resize(noff, ident_stack{*ts.pstate});
-    });
+    };
+    try {
+        body();
+    } catch (...) {
+        cleanup();
+        throw;
+    }
+    cleanup();
 }
 
 void exec_command(