diff --git a/libc/cmake/modules/prepare_libc_gpu_build.cmake b/libc/cmake/modules/prepare_libc_gpu_build.cmake
--- a/libc/cmake/modules/prepare_libc_gpu_build.cmake
+++ b/libc/cmake/modules/prepare_libc_gpu_build.cmake
@@ -46,11 +46,11 @@
 if(LIBC_GPU_TEST_ARCHITECTURE)
   message(STATUS "Using user-specified GPU architecture for testing "
                  "'${LIBC_GPU_TARGET_ARCHITECTURE}'")
-  if("${LIBC_GPU_TARGET_ARCHITECTURE}" IN_LIST all_amdgpu_architectures)
+  if("${LIBC_GPU_TEST_ARCHITECTURE}" IN_LIST all_amdgpu_architectures)
     set(LIBC_GPU_TARGET_ARCHITECTURE_IS_AMDGPU TRUE)
     set(LIBC_GPU_TARGET_TRIPLE "amdgcn-amd-amdhsa")
     set(LIBC_GPU_TARGET_ARCHITECTURE "${LIBC_GPU_TEST_ARCHITECTURE}")
-  elseif("${LIBC_GPU_TARGET_ARCHITECTURE}" IN_LIST all_nvptx_architectures)
+  elseif("${LIBC_GPU_TEST_ARCHITECTURE}" IN_LIST all_nvptx_architectures)
     set(LIBC_GPU_TARGET_ARCHITECTURE_IS_NVPTX TRUE)
     set(LIBC_GPU_TARGET_TRIPLE "nvptx64-nvidia-cuda")
     set(LIBC_GPU_TARGET_ARCHITECTURE "${LIBC_GPU_TEST_ARCHITECTURE}")