diff --git a/ci/rtools/BuildAwsCCommon.patch b/ci/rtools/BuildAwsCCommon.patch
index ab056e0055dca..f129b6f12344d 100644
--- a/ci/rtools/BuildAwsCCommon.patch
+++ b/ci/rtools/BuildAwsCCommon.patch
@@ -52,15 +52,3 @@ index 1204be0..0abd9cb 100644
      return _byteswap_uint64(x);
  #else
      uint32_t low = x & UINT32_MAX;
-diff --git a/source/windows/thread.c b/source/windows/thread.c
-index 447fcd2..01e643f 100644
---- a/source/windows/thread.c
-+++ b/source/windows/thread.c
-@@ -10,6 +10,7 @@
- #include <aws/common/private/thread_shared.h>
- #include <aws/common/string.h>
-
-+#define _WIN32_WINNT 0x0601
- #include <Windows.h>
-
- #include <inttypes.h>
diff --git a/cpp/cmake_modules/ThirdpartyToolchain.cmake b/cpp/cmake_modules/ThirdpartyToolchain.cmake
index 59a2db7b8198a..db208e89e3564 100644
--- a/cpp/cmake_modules/ThirdpartyToolchain.cmake
+++ b/cpp/cmake_modules/ThirdpartyToolchain.cmake
@@ -5039,6 +5039,12 @@ macro(build_awssdk)
     string(APPEND AWS_C_FLAGS " -Wno-deprecated")
     string(APPEND AWS_CXX_FLAGS " -Wno-deprecated")
   endif()
+  # GH-44950: This is required to build under Rtools40 and we may be able to
+  # remove it if/when we no longer need to build under Rtools40
+  if(WIN32 AND NOT MSVC)
+    string(APPEND AWS_C_FLAGS " -D_WIN32_WINNT=0x0601")
+    string(APPEND AWS_CXX_FLAGS " -D_WIN32_WINNT=0x0601")
+  endif()
 
   set(AWSSDK_COMMON_CMAKE_ARGS
       ${EP_COMMON_CMAKE_ARGS}