diff --git a/scripts/ci/github-install-deps.sh b/scripts/ci/github-install-deps.sh
index 6d6cf57..e351914 100755
--- a/scripts/ci/github-install-deps.sh
+++ b/scripts/ci/github-install-deps.sh
@@ -7,7 +7,8 @@ cd "$ROOT"
 
 export GIT_TERMINAL_PROMPT=0
 
-# pycodec2 builds against libcodec2
+# pycodec2 builds against libcodec2. Export for this step and persist to GITHUB_ENV so
+# later steps (e.g. pip install -e . for the x64 universal slice) see the same flags.
 if [[ "$(uname -s)" == "Darwin" ]]; then
     brew install codec2
     _codec2_prefix="$(brew --prefix codec2)"
@@ -16,6 +17,13 @@ if [[ "$(uname -s)" == "Darwin" ]]; then
     if [[ -d "${_codec2_prefix}/lib/pkgconfig" ]]; then
         export PKG_CONFIG_PATH="${_codec2_prefix}/lib/pkgconfig:${PKG_CONFIG_PATH:-}"
     fi
+    if [[ -n "${GITHUB_ENV:-}" ]]; then
+        {
+            echo "CPPFLAGS=${CPPFLAGS}"
+            echo "LDFLAGS=${LDFLAGS}"
+            echo "PKG_CONFIG_PATH=${PKG_CONFIG_PATH:-}"
+        } >> "$GITHUB_ENV"
+    fi
 fi
 
 python -m poetry install --no-interaction --no-ansi