diff --git a/browser_patches/checkout_build_archive_upload.sh b/browser_patches/checkout_build_archive_upload.sh
index 7c4e42606c..41edbb1b0b 100755
--- a/browser_patches/checkout_build_archive_upload.sh
+++ b/browser_patches/checkout_build_archive_upload.sh
@@ -249,6 +249,8 @@ elif [[ "$BUILD_FLAVOR" == "firefox-beta-win64" ]]; then
   EXTRA_BUILD_ARGS="--full"
   EXPECTED_HOST_OS="MINGW"
   BUILD_BLOB_NAME="firefox-beta-win64.zip"
+  # This is the architecture that is set by mozilla-build bash.
+  EXPECTED_ARCH="i686"
 
 # ===========================
 #    WEBKIT COMPILATION
diff --git a/browser_patches/firefox-beta/build.sh b/browser_patches/firefox-beta/build.sh
index 4370da6848..7c8b32c610 100755
--- a/browser_patches/firefox-beta/build.sh
+++ b/browser_patches/firefox-beta/build.sh
@@ -96,8 +96,6 @@ if [[ $1 == "--full" || $2 == "--full" || $1 == "--bootstrap" ]]; then
   if [[ ! -z "${WIN32_REDIST_DIR}" ]]; then
     # Having this option in .mozconfig kills incremental compilation.
     echo "export WIN32_REDIST_DIR=\"$WIN32_REDIST_DIR\"" >> .mozconfig
-    echo "export MSVC_C_RUNTIME_DLL=vcruntime140.dll" >> .mozconfig
-    echo "export MSVC_CXX_RUNTIME_DLL=msvcp140.dll" >> .mozconfig
   fi
 fi