diff --git a/build_proton.sh b/build_proton.sh
index 7c370250..d1b32e09 100755
--- a/build_proton.sh
+++ b/build_proton.sh
@@ -8,6 +8,8 @@ set -e
 
 TOP="$PWD"
 RUNTIME_PATH="$TOP/../../runtime/steam-runtime-both/"
+AMD64_WRAPPER="schroot --chroot steamrt_scout_beta_amd64 --"
+I386_WRAPPER="schroot --chroot steamrt_scout_beta_i386 --"
 DST_DIR="$TOP/build/dist"
 TOOLS_DIR64="$TOP/build/tools.win64"
 TOOLS_DIR32="$TOP/build/tools.win32"
@@ -16,17 +18,17 @@ mkdir -p dist "$DST_DIR"/bin build/wine.win32 build/dist.win32 build/wine.win64
 
 #build wine64
 cd "$TOP"/build/wine.win64
-CC="ccache gcc" "$RUNTIME_PATH/shell-amd64.sh" "$TOP"/wine/configure --enable-win64 --disable-tests --prefix="$DST_DIR"
-"$RUNTIME_PATH/shell-amd64.sh" make
-"$RUNTIME_PATH/shell-amd64.sh" make install-lib
-"$RUNTIME_PATH/shell-amd64.sh" make prefix="$TOOLS_DIR64" libdir="$TOOLS_DIR64/lib64" dlldir="$TOOLS_DIR64/lib64/wine" install-dev install-lib
+CC="ccache gcc" $AMD64_WRAPPER "$TOP"/wine/configure --enable-win64 --disable-tests --prefix="$DST_DIR"
+$AMD64_WRAPPER make -j5
+$AMD64_WRAPPER make install-lib
+$AMD64_WRAPPER make prefix="$TOOLS_DIR64" libdir="$TOOLS_DIR64/lib64" dlldir="$TOOLS_DIR64/lib64/wine" install-dev install-lib
 
 #build wine32
 cd "$TOP"/build/wine.win32
-CC="ccache gcc" "$RUNTIME_PATH/shell-i386.sh" "$TOP"/wine/configure --disable-tests --prefix="$TOP/build/dist.win32/"
-"$RUNTIME_PATH/shell-i386.sh" make
-"$RUNTIME_PATH/shell-i386.sh" make install-lib
-"$RUNTIME_PATH/shell-i386.sh" make prefix="$TOOLS_DIR32" libdir="$TOOLS_DIR32/lib" dlldir="$TOOLS_DIR32/lib/wine" install-dev install-lib
+CC="ccache gcc" $I386_WRAPPER "$TOP"/wine/configure --disable-tests --prefix="$TOP/build/dist.win32/"
+$I386_WRAPPER make -j5
+$I386_WRAPPER make install-lib
+$I386_WRAPPER make prefix="$TOOLS_DIR32" libdir="$TOOLS_DIR32/lib" dlldir="$TOOLS_DIR32/lib/wine" install-dev install-lib
 
 #install 32-bit stuff manually, see
 # https://wiki.winehq.org/Packaging#WoW64_Workarounds
@@ -41,7 +43,7 @@ cd "$TOP"
 rm -rf build/lsteamclient.win64
 cp -a lsteamclient build/lsteamclient.win64
 cd "$TOP"/build/lsteamclient.win64/
-"$RUNTIME_PATH/shell-amd64.sh" "$TOP"/wine/tools/winemaker/winemaker \
+$AMD64_WRAPPER "$TOP"/wine/tools/winemaker/winemaker \
     --nosource-fix --nolower-include --nodlls --nomsvcrt \
     -DSTEAM_API_EXPORTS \
     -I"$TOOLS_DIR64"/include/ \
@@ -50,7 +52,7 @@ cd "$TOP"/build/lsteamclient.win64/
     -L"$TOOLS_DIR64"/lib64/ \
     -L"$TOOLS_DIR64"/lib64/wine/ \
     --dll .
-CXXFLAGS=-Wno-attributes PATH="$TOOLS_DIR64/bin:$PATH" "$RUNTIME_PATH/shell-amd64.sh" make
+CXXFLAGS=-Wno-attributes PATH="$TOOLS_DIR64/bin:$PATH" $AMD64_WRAPPER make
 cp -a lsteamclient.dll.so "$DST_DIR"/lib64/wine/
 
 #build 32-bit lsteamclient
@@ -58,7 +60,7 @@ cd "$TOP"
 rm -rf build/lsteamclient.win32
 cp -a lsteamclient build/lsteamclient.win32
 cd "$TOP"/build/lsteamclient.win32/
-"$RUNTIME_PATH/shell-i386.sh" "$TOP"/wine/tools/winemaker/winemaker \
+$I386_WRAPPER "$TOP"/wine/tools/winemaker/winemaker \
     --nosource-fix --nolower-include --nodlls --nomsvcrt --wine32 \
     -DSTEAM_API_EXPORTS \
     -I"$TOOLS_DIR32"/include/ \
@@ -67,7 +69,7 @@ cd "$TOP"/build/lsteamclient.win32/
     -L"$TOOLS_DIR32"/lib/ \
     -L"$TOOLS_DIR32"/lib/wine/ \
     --dll .
-CXXFLAGS=-Wno-attributes PATH="$TOOLS_DIR32/bin:$PATH" "$RUNTIME_PATH/shell-i386.sh" make -j1
+CXXFLAGS=-Wno-attributes PATH="$TOOLS_DIR32/bin:$PATH" $I386_WRAPPER make -j1
 cp -a lsteamclient.dll.so "$DST_DIR"/lib/wine/
 
 #build 64-bit vrclient
@@ -75,7 +77,7 @@ cd "$TOP"
 rm -rf build/vrclient_x64
 cp -a vrclient_x64 build/vrclient_x64
 cd "$TOP"/build/vrclient_x64/
-"$RUNTIME_PATH/shell-amd64.sh" "$TOP"/wine/tools/winemaker/winemaker \
+$AMD64_WRAPPER "$TOP"/wine/tools/winemaker/winemaker \
     --nosource-fix --nolower-include --nodlls --nomsvcrt \
     -I"$TOOLS_DIR64"/include/ \
     -I"$TOOLS_DIR64"/include/wine/ \
@@ -83,8 +85,8 @@ cd "$TOP"/build/vrclient_x64/
     -L"$TOOLS_DIR64"/lib64/ \
     -L"$TOOLS_DIR64"/lib64/wine/ \
     --dll .
-CXXFLAGS="-Wno-attributes -std=c++0x" PATH="$TOOLS_DIR64/bin:$PATH" "$RUNTIME_PATH/shell-amd64.sh" make
-PATH="$TOOLS_DIR64/bin:$PATH" "$RUNTIME_PATH/shell-amd64.sh" winebuild --dll --fake-module -E vrclient_x64.spec -o vrclient_x64.dll.fake
+CXXFLAGS="-Wno-attributes -std=c++0x" PATH="$TOOLS_DIR64/bin:$PATH" $AMD64_WRAPPER make
+PATH="$TOOLS_DIR64/bin:$PATH" $AMD64_WRAPPER winebuild --dll --fake-module -E vrclient_x64.spec -o vrclient_x64.dll.fake
 cp -a vrclient_x64.dll.so "$DST_DIR"/lib64/wine/
 cp -a vrclient_x64.dll.fake "$DST_DIR"/lib64/wine/fakedlls/vrclient_x64.dll
 
@@ -94,7 +96,7 @@ rm -rf build/vrclient
 cp -a vrclient_x64 build/vrclient
 cd "$TOP"/build/vrclient/
 mv vrclient_x64.spec vrclient.spec
-"$RUNTIME_PATH/shell-i386.sh" "$TOP"/wine/tools/winemaker/winemaker \
+$I386_WRAPPER "$TOP"/wine/tools/winemaker/winemaker \
     --nosource-fix --nolower-include --nodlls --nomsvcrt --wine32 \
     -I"$TOOLS_DIR32"/include/ \
     -I"$TOOLS_DIR32"/include/wine/ \
@@ -102,16 +104,16 @@ mv vrclient_x64.spec vrclient.spec
     -L"$TOOLS_DIR32"/lib/ \
     -L"$TOOLS_DIR32"/lib/wine/ \
     --dll .
-CXXFLAGS="-Wno-attributes -std=c++0x" PATH="$TOOLS_DIR32/bin:$PATH" "$RUNTIME_PATH/shell-i386.sh" make
-PATH="$TOOLS_DIR32/bin:$PATH" "$RUNTIME_PATH/shell-i386.sh" winebuild --dll --fake-module -E vrclient.spec -o vrclient.dll.fake
+CXXFLAGS="-Wno-attributes -std=c++0x" PATH="$TOOLS_DIR32/bin:$PATH" $I386_WRAPPER make
+PATH="$TOOLS_DIR32/bin:$PATH" $I386_WRAPPER winebuild --dll --fake-module -E vrclient.spec -o vrclient.dll.fake
 cp -a vrclient.dll.so "$DST_DIR"/lib/wine/
 cp -a vrclient.dll.fake "$DST_DIR"/lib/wine/fakedlls/vrclient.dll
 
 echo "Creating default wine prefix..."
 cd "$TOP"
 rm -rf "$DST_DIR"/share/default_pfx
-WINEPREFIX="$DST_DIR"/share/default_pfx "$RUNTIME_PATH/shell-amd64.sh" "$DST_DIR/bin/wine64" wineboot
-WINEPREFIX="$DST_DIR"/share/default_pfx "$RUNTIME_PATH/shell-amd64.sh" "$DST_DIR/bin/wineserver" -w
+WINEPREFIX="$DST_DIR"/share/default_pfx $AMD64_WRAPPER "$DST_DIR/bin/wine64" wineboot
+WINEPREFIX="$DST_DIR"/share/default_pfx $AMD64_WRAPPER "$DST_DIR/bin/wineserver" -w
 
 echo "Packaging..."
 cd "$TOP"