diff --git a/generate.sh b/generate.sh
index b0142be..6280c35 100755
--- a/generate.sh
+++ b/generate.sh
@@ -11,12 +11,8 @@ to_df() {
 }
 
 to_df "FROM $REPO:base-$TARGET"
-to_df "ENV TARGET $TARGET"
-to_df "ENV VARIANT $VARIANT"
-to_df "ENV REPO $REPO"
-
-to_df "ENV FFPREFIX /opt/ffbuild"
-to_df "ENV PKG_CONFIG_LIBDIR /opt/ffbuild/lib/pkgconfig"
+to_df "ENV TARGET=$TARGET VARIANT=$VARIANT REPO=$REPO"
+to_df "ENV FFBUILD_PREFIX=/opt/ffbuild PKG_CONFIG_LIBDIR=/opt/ffbuild/lib/pkgconfig"
 
 for script in scripts.d/*.sh; do
 (
diff --git a/images/base-win64/Dockerfile b/images/base-win64/Dockerfile
index ad20bf3..2ddb363 100644
--- a/images/base-win64/Dockerfile
+++ b/images/base-win64/Dockerfile
@@ -7,3 +7,5 @@ RUN \
     apt-get -y clean
 
 ENV FFBUILD_TARGET_FLAGS "--pkg-config=pkg-config --cross-prefix=x86_64-w64-mingw32- --arch=x86_64 --target-os=win32"
+ENV FFBUILD_TOOLCHAIN x86_64-w64-mingw32
+ENV FFBUILD_CROSS_PREFIX x86_64-w64-mingw32-
diff --git a/scripts.d/50-x264.sh b/scripts.d/50-x264.sh
index bb93b55..ca662fa 100755
--- a/scripts.d/50-x264.sh
+++ b/scripts.d/50-x264.sh
@@ -10,24 +10,34 @@ ffbuild_enabled() {
 
 ffbuild_dockerstage() {
     to_df "ADD $SELF /root/x264.sh"
-    to_df "RUN bash -c 'source /root/x264.sh && ffbuild_dockerbuild'"
+    to_df "RUN bash -c 'source /root/x264.sh && ffbuild_dockerbuild && rm /root/x264.sh'"
 }
 
 ffbuild_dockerbuild() {
     git clone "$X264_REPO" x264 || return -1
     pushd x264
-    git checkout "$X264_COMMIT" || return -1
+    git switch "$X264_COMMIT" || return -1
 
-    if [[ $TARGET == win64 ]]; then
-        ./configure --disable-cli --enable-static --enable-pic \
-                    --disable-lavf --disable-swscale \
-                    --host=x86_64-w64-mingw32 --cross-prefix=x86_64-w64-mingw32- \
-                    --prefix="$FFPREFIX" || return -1
+    local myconf=(
+        --disable-cli
+        --enable-static
+        --enable-pic
+        --disable-lavf
+        --disable-swscale
+        --prefix="$FFBUILD_PREFIX"
+    )
+
+    if [[ $TARGET == win* ]]; then
+        myconf+=(
+            --host="$FFBUILD_TOOLCHAIN"
+            --cross-prefix="$FFBUILD_CROSS_PREFIX"
+        )
     else
         echo "Unknown target"
         return -1
     fi
 
+    ./configure "${myconf[@]}" || return -1
     make -j$(nproc) || return -1
     make install || return -1