diff --git a/arch/sim/include/math.h b/arch/sim/include/math.h
deleted file mode 100644
index 7126027332c..00000000000
--- a/arch/sim/include/math.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/****************************************************************************
- * arch/sim/include/math.h
- *
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.  The
- * ASF licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the
- * License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
- * License for the specific language governing permissions and limitations
- * under the License.
- *
- ****************************************************************************/
-
-#ifndef __ARCH_SIM_INCLUDE_MATH_H
-#define __ARCH_SIM_INCLUDE_MATH_H
-
-/****************************************************************************
- * Included Files
- ****************************************************************************/
-
-#include_next <math.h>
-
-#ifdef __GLIBC__
-#undef __GLIBC__
-#endif
-
-#endif /* __ARCH_SIM_INCLUDE_MATH_H */
diff --git a/boards/sim/sim/sim/configs/libcxxtest/defconfig b/boards/sim/sim/sim/configs/libcxxtest/defconfig
index 98735fa9869..608014f9546 100644
--- a/boards/sim/sim/sim/configs/libcxxtest/defconfig
+++ b/boards/sim/sim/sim/configs/libcxxtest/defconfig
@@ -10,7 +10,6 @@ CONFIG_ARCH="sim"
 CONFIG_ARCH_BOARD="sim"
 CONFIG_ARCH_BOARD_SIM=y
 CONFIG_ARCH_CHIP="sim"
-CONFIG_ARCH_MATH_H=y
 CONFIG_ARCH_SIM=y
 CONFIG_BOARDCTL_APP_SYMTAB=y
 CONFIG_BOARDCTL_POWEROFF=y
diff --git a/libs/libxx/0001-Fix-build-error-about-__GLIBC__.patch b/libs/libxx/0001-Fix-build-error-about-__GLIBC__.patch
new file mode 100644
index 00000000000..95d6ee09dff
--- /dev/null
+++ b/libs/libxx/0001-Fix-build-error-about-__GLIBC__.patch
@@ -0,0 +1,17 @@
+diff --git libcxx/src/locale.cpp libcxx/src/locale.cpp
+--- libcxx/src/locale.cpp
++++ libcxx/src/locale.cpp
+@@ -41,6 +41,10 @@
+ #include "include/atomic_support.h"
+ #include "include/sso_allocator.h"
+
++#if defined(__NuttX__) && defined(__GLIBC__)
++#   undef __GLIBC__
++#endif
++
+ // On Linux, wint_t and wchar_t have different signed-ness, and this causes
+ // lots of noise in the build log, but no bugs that I know of.
+ _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wsign-conversion")
+--
+2.34.1
+
diff --git a/libs/libxx/libcxx.cmake b/libs/libxx/libcxx.cmake
index 9b4c3fee88d..c88568f1322 100644
--- a/libs/libxx/libcxx.cmake
+++ b/libs/libxx/libcxx.cmake
@@ -49,7 +49,9 @@ if(NOT EXISTS ${CMAKE_CURRENT_LIST_DIR}/libcxx)
       ${CMAKE_CURRENT_LIST_DIR}/libcxx <
       ${CMAKE_CURRENT_LIST_DIR}/0001-libcxx-remove-mach-time-h.patch && patch
       -p1 -d ${CMAKE_CURRENT_LIST_DIR}/libcxx <
-      ${CMAKE_CURRENT_LIST_DIR}/0001-libcxx-fix-ld-errors.patch
+      ${CMAKE_CURRENT_LIST_DIR}/0001-libcxx-fix-ld-errors.patch && patch -p1 -d
+      ${CMAKE_CURRENT_LIST_DIR}/libcxx <
+      ${CMAKE_CURRENT_LIST_DIR}/0001-Fix-build-error-about-__GLIBC__.patch
     DOWNLOAD_NO_PROGRESS true
     TIMEOUT 30)
 
diff --git a/libs/libxx/libcxx.defs b/libs/libxx/libcxx.defs
index 717af3489e6..192a6734a1e 100644
--- a/libs/libxx/libcxx.defs
+++ b/libs/libxx/libcxx.defs
@@ -35,6 +35,7 @@ libcxx: libcxx-$(LIBCXX_VERSION).src.tar.xz
 	$(Q) patch -p2 < mbstate_t.patch
 	$(Q) patch -p0 < 0001-libcxx-remove-mach-time-h.patch
 	$(Q) patch -p0 < 0001-libcxx-fix-ld-errors.patch
+	$(Q) patch -p0 < 0001-Fix-build-error-about-__GLIBC__.patch
 	$(Q) touch $@
 endif