diff --git a/include/cubescript/cubescript.hh b/include/cubescript/cubescript.hh
index 0f36991f..18b8d369 100644
--- a/include/cubescript/cubescript.hh
+++ b/include/cubescript/cubescript.hh
@@ -6,12 +6,12 @@
 
 #include <optional>
 #include <functional>
+#include <type_traits>
 
 #include "cubescript_conf.hh"
 
 #include <ostd/platform.hh>
 #include <ostd/types.hh>
-#include <ostd/type_traits.hh>
 #include <ostd/string.hh>
 #include <ostd/vector.hh>
 #include <ostd/range.hh>
@@ -23,9 +23,9 @@ namespace cscript {
 
 using CsString = std::string;
 
-static_assert(ostd::IsIntegral<CsInt>, "CsInt must be integral");
-static_assert(ostd::IsSigned<CsInt>, "CsInt must be signed");
-static_assert(ostd::IsFloatingPoint<CsFloat>, "CsFloat must be floating point");
+static_assert(std::is_integral_v<CsInt>, "CsInt must be integral");
+static_assert(std::is_signed_v<CsInt>, "CsInt must be signed");
+static_assert(std::is_floating_point_v<CsFloat>, "CsFloat must be floating point");
 
 enum {
     CsIdfPersist    = 1 << 0,
@@ -108,7 +108,7 @@ struct OSTD_EXPORT CsValue {
     bool code_is_empty() const;
 
 private:
-    ostd::AlignedUnion<1, CsInt, CsFloat, void *> p_stor;
+    std::aligned_union_t<1, CsInt, CsFloat, void *> p_stor;
     size_t p_len;
     CsValueType p_type;
 };
diff --git a/src/cs_gen.cc b/src/cs_gen.cc
index b631d500..4da0464e 100644
--- a/src/cs_gen.cc
+++ b/src/cs_gen.cc
@@ -4,7 +4,7 @@
 
 #include <ctype.h>
 
-#include <ostd/limits.hh>
+#include <limits>
 
 namespace cscript {
 
@@ -354,7 +354,7 @@ lookupid:
                                     numargs++;
                                     break;
                                 case 'b':
-                                    gs.gen_int(ostd::NumericLimitMin<CsInt>);
+                                    gs.gen_int(std::numeric_limits<CsInt>::min());
                                     numargs++;
                                     break;
                                 case 'f':
@@ -942,7 +942,7 @@ static void compile_cmd(
                     if (rep) {
                         break;
                     }
-                    gs.gen_int(ostd::NumericLimitMin<CsInt>);
+                    gs.gen_int(std::numeric_limits<CsInt>::min());
                     fakeargs++;
                 }
                 numargs++;
diff --git a/src/cs_util.hh b/src/cs_util.hh
index 70c3bce5..38973870 100644
--- a/src/cs_util.hh
+++ b/src/cs_util.hh
@@ -1,9 +1,10 @@
 #ifndef LIBCUBESCRIPT_CS_UTIL_HH
 #define LIBCUBESCRIPT_CS_UTIL_HH
 
+#include <type_traits>
+
 #include <ostd/string.hh>
 #include <ostd/utility.hh>
-#include <ostd/type_traits.hh>
 #include <ostd/unordered_map.hh>
 
 namespace cscript {
@@ -29,7 +30,7 @@ struct CsScopeExit {
     ~CsScopeExit() {
         func();
     }
-    ostd::Decay<F> func;
+    std::decay_t<F> func;
 };
 
 template<typename F1, typename F2>
diff --git a/src/cs_vm.cc b/src/cs_vm.cc
index 9eb73743..fc5a53d0 100644
--- a/src/cs_vm.cc
+++ b/src/cs_vm.cc
@@ -2,7 +2,7 @@
 #include "cs_vm.hh"
 #include "cs_util.hh"
 
-#include <ostd/limits.hh>
+#include <limits>
 
 namespace cscript {
 
@@ -322,7 +322,7 @@ static inline void callcommand(
                     if (rep) {
                         break;
                     }
-                    args[i].set_int(ostd::NumericLimitMin<CsInt>);
+                    args[i].set_int(std::numeric_limits<CsInt>::min());
                     fakeargs++;
                 } else {
                     args[i].force_int();
diff --git a/src/lib_math.cc b/src/lib_math.cc
index f01f52c8..dde2cab8 100644
--- a/src/lib_math.cc
+++ b/src/lib_math.cc
@@ -1,5 +1,6 @@
 #include <cstdlib>
 #include <cmath>
+#include <climits>
 #include <functional>
 #include <algorithm>
 
@@ -243,7 +244,7 @@ void cs_init_lib_math(CsState &cs) {
     cs.new_command("<<", "i1V", [](auto &, auto args, auto &res) {
         cs_mathop<CsInt>(
             args, res, 0, [](CsInt val1, CsInt val2) {
-                return (val2 < CsInt(ostd::SizeInBits<CsInt>))
+                return (val2 < CsInt(sizeof(CsInt) * CHAR_BIT))
                     ? (val1 << std::max(val2, CsInt(0)))
                     : 0;
             }, CsMathNoop<CsInt>()
@@ -253,7 +254,7 @@ void cs_init_lib_math(CsState &cs) {
         cs_mathop<CsInt>(
             args, res, 0, [](CsInt val1, CsInt val2) {
                 return val1 >> std::clamp(
-                    val2, CsInt(0), CsInt(ostd::SizeInBits<CsInt>)
+                    val2, CsInt(0), CsInt(sizeof(CsInt) * CHAR_BIT)
                 );
             }, CsMathNoop<CsInt>()
         );