diff --git a/.github/scripts/args-debug.gn b/.github/scripts/args-debug.gn
index f0acb13..a1edf75 100644
--- a/.github/scripts/args-debug.gn
+++ b/.github/scripts/args-debug.gn
@@ -23,4 +23,4 @@ v8_third_party_heap_files = [
     "$the_root/v8/third_party/heap/mmtk/mmtkUpcalls.h",
     "$the_root/v8/third_party/heap/mmtk/mmtkUpcalls.cc"
 ]
-v8_third_party_heap_libs = [ "$the_root/mmtk/target/debug/libmmtk_v8.so" ]
+v8_third_party_heap_libs = [ "$the_root/mmtk/target/x86_64-unknown-linux-gnu/debug/libmmtk_v8.so" ]
diff --git a/.github/scripts/args-optdebug.gn b/.github/scripts/args-optdebug.gn
index ec9bd6a..9add4de 100644
--- a/.github/scripts/args-optdebug.gn
+++ b/.github/scripts/args-optdebug.gn
@@ -22,4 +22,4 @@ v8_third_party_heap_files = [
     "$the_root/v8/third_party/heap/mmtk/mmtkUpcalls.h",
     "$the_root/v8/third_party/heap/mmtk/mmtkUpcalls.cc"
 ]
-v8_third_party_heap_libs = [ "$the_root/mmtk/target/debug/libmmtk_v8.so" ]
+v8_third_party_heap_libs = [ "$the_root/mmtk/target/x86_64-unknown-linux-gnu/debug/libmmtk_v8.so" ]
diff --git a/.github/scripts/build-mmtk.sh b/.github/scripts/build-mmtk.sh
index 6471fa5..405b677 100755
--- a/.github/scripts/build-mmtk.sh
+++ b/.github/scripts/build-mmtk.sh
@@ -2,6 +2,15 @@ set -xe
 
 . $(dirname "$0")/common.sh
 
+export PATH=~/.cargo/bin:$PATH
+# Check if we have cross available
+if ! [ -x "$(command -v cross)" ]; then
+  echo 'Cross is not available. Will install cross.' >&2
+  # lock to version 0.2.4. This version uses libc 2.31 for x86_64.
+  # This matches the version in the sysroot used by V8 (debian bullseye)
+  cargo install cross@0.2.4 --git https://github.com/cross-rs/cross
+fi
+
 # simply build mmtk-v8 with nogc
 cd $THE_ROOT/mmtk
-rustup run $RUSTUP_TOOLCHAIN cargo build --features nogc
+cross build --target x86_64-unknown-linux-gnu --features nogc
diff --git a/.github/scripts/common.sh b/.github/scripts/common.sh
index cf58cc2..3cb12ce 100644
--- a/.github/scripts/common.sh
+++ b/.github/scripts/common.sh
@@ -5,8 +5,8 @@ export THE_ROOT=`realpath $(dirname "$0")/../..`
 export V8_ROOT=$THE_ROOT/deps
 
 # Test with a specific revision.
-export V8_VERSION=`cargo read-manifest --manifest-path=$THE_ROOT/mmtk/Cargo.toml | python -c 'import json,sys; print(json.load(sys.stdin)["metadata"]["v8"]["v8_version"])'`
+export V8_VERSION=`cargo read-manifest --manifest-path=$THE_ROOT/mmtk/Cargo.toml | python3 -c 'import json,sys; print(json.load(sys.stdin)["metadata"]["v8"]["v8_version"])'`
 # The commit after this requires python 3.7. This is the only reason we fix to this revision.
-export DEPOT_TOOLS_VERSION=`cargo read-manifest --manifest-path=$THE_ROOT/mmtk/Cargo.toml | python -c 'import json,sys; print(json.load(sys.stdin)["metadata"]["v8"]["depot_tools_version"])'`
+export DEPOT_TOOLS_VERSION=`cargo read-manifest --manifest-path=$THE_ROOT/mmtk/Cargo.toml | python3 -c 'import json,sys; print(json.load(sys.stdin)["metadata"]["v8"]["depot_tools_version"])'`
 
 export RUSTUP_TOOLCHAIN=`cat $THE_ROOT/mmtk/rust-toolchain`