diff --git a/scripts/install.sh b/scripts/install.sh
index ab305544bd..d452a26490 100755
--- a/scripts/install.sh
+++ b/scripts/install.sh
@@ -28,6 +28,10 @@ if [ -n "${PYTHONHOME:-}" ]; then
     unset PYTHONHOME
 fi
 
+# Prevent uv from discovering config files (uv.toml, pyproject.toml) from the
+# wrong user's home directory when running under sudo -u <user>.  See #21269.
+export UV_NO_CONFIG=1
+
 # Colors
 RED='\033[0;31m'
 GREEN='\033[0;32m'
diff --git a/setup-hermes.sh b/setup-hermes.sh
index 5d0f2928ab..4d83f94ffb 100755
--- a/setup-hermes.sh
+++ b/setup-hermes.sh
@@ -29,6 +29,10 @@ NC='\033[0m'
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 cd "$SCRIPT_DIR"
 
+# Prevent uv from discovering config files (uv.toml, pyproject.toml) from the
+# wrong user's home directory when running under sudo -u <user>.  See #21269.
+export UV_NO_CONFIG=1
+
 PYTHON_VERSION="3.11"
 
 is_termux() {