diff --git a/libcxx/cmake/caches/Armv7.cmake b/libcxx/cmake/caches/Armv7Arm.cmake
rename from libcxx/cmake/caches/Armv7.cmake
rename to libcxx/cmake/caches/Armv7Arm.cmake
--- a/libcxx/cmake/caches/Armv7.cmake
+++ b/libcxx/cmake/caches/Armv7Arm.cmake
@@ -1,2 +1,4 @@
 set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
 set(LIBCXX_TARGET_TRIPLE "armv7-linux-gnueabihf" CACHE STRING "")
+set(CMAKE_CXX_FLAGS "-marm" CACHE STRING "")
+set(CMAKE_C_FLAGS "-marm" CACHE STRING "")
diff --git a/libcxx/cmake/caches/Armv7.cmake b/libcxx/cmake/caches/Armv7Thumb.cmake
rename from libcxx/cmake/caches/Armv7.cmake
rename to libcxx/cmake/caches/Armv7Thumb.cmake
--- a/libcxx/cmake/caches/Armv7.cmake
+++ b/libcxx/cmake/caches/Armv7Thumb.cmake
@@ -1,2 +1,4 @@
 set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
 set(LIBCXX_TARGET_TRIPLE "armv7-linux-gnueabihf" CACHE STRING "")
+set(CMAKE_CXX_FLAGS "-mthumb" CACHE STRING "")
+set(CMAKE_C_FLAGS "-mthumb" CACHE STRING "")
diff --git a/libcxx/cmake/caches/Armv8.cmake b/libcxx/cmake/caches/Armv8Arm.cmake
rename from libcxx/cmake/caches/Armv8.cmake
rename to libcxx/cmake/caches/Armv8Arm.cmake
--- a/libcxx/cmake/caches/Armv8.cmake
+++ b/libcxx/cmake/caches/Armv8Arm.cmake
@@ -1,2 +1,4 @@
 set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
 set(LIBCXX_TARGET_TRIPLE "armv8-linux-gnueabihf" CACHE STRING "")
+set(CMAKE_CXX_FLAGS "-marm" CACHE STRING "")
+set(CMAKE_C_FLAGS "-marm" CACHE STRING "")
diff --git a/libcxx/cmake/caches/Armv8.cmake b/libcxx/cmake/caches/Armv8Thumb.cmake
rename from libcxx/cmake/caches/Armv8.cmake
rename to libcxx/cmake/caches/Armv8Thumb.cmake
--- a/libcxx/cmake/caches/Armv8.cmake
+++ b/libcxx/cmake/caches/Armv8Thumb.cmake
@@ -1,2 +1,4 @@
 set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
 set(LIBCXX_TARGET_TRIPLE "armv8-linux-gnueabihf" CACHE STRING "")
+set(CMAKE_CXX_FLAGS "-mthumb" CACHE STRING "")
+set(CMAKE_C_FLAGS "-mthumb" CACHE STRING "")
diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -402,16 +402,12 @@
 # Aka Armv8 32 bit
 armv8)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8.cmake" \
-    -DCMAKE_CXX_FLAGS="-marm" \
-    -DCMAKE_C_FLAGS="-marm"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Arm.cmake"
     check-cxx-cxxabi
 ;;
 armv8-noexceptions)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8.cmake" \
-    -DCMAKE_CXX_FLAGS="-mthumb" \
-    -DCMAKE_C_FLAGS="-mthumb" \
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Thumb.cmake" \
     -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
     -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF
     check-cxx-cxxabi
@@ -419,16 +415,12 @@
 # Armv7 32 bit. One building Arm only one Thumb only code.
 armv7)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7.cmake" \
-    -DCMAKE_CXX_FLAGS="-marm" \
-    -DCMAKE_C_FLAGS="-marm"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Arm.cmake"
     check-cxx-cxxabi
 ;;
 armv7-noexceptions)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7.cmake" \
-    -DCMAKE_CXX_FLAGS="-mthumb" \
-    -DCMAKE_C_FLAGS="-mthumb" \
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Thumb.cmake" \
     -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
     -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF
     check-cxx-cxxabi