diff --git a/Cargo.lock b/Cargo.lock
index ef99775..c679bb0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1642,7 +1642,7 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "lesavka_client"
-version = "0.14.26"
+version = "0.14.27"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -1676,7 +1676,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_common"
-version = "0.14.26"
+version = "0.14.27"
 dependencies = [
  "anyhow",
  "base64",
@@ -1688,7 +1688,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_server"
-version = "0.14.26"
+version = "0.14.27"
 dependencies = [
  "anyhow",
  "base64",
diff --git a/client/Cargo.toml b/client/Cargo.toml
index d24dc95..d02a844 100644
--- a/client/Cargo.toml
+++ b/client/Cargo.toml
@@ -4,7 +4,7 @@ path                    = "src/main.rs"
 
 [package]
 name                    = "lesavka_client"
-version                 = "0.14.26"
+version                 = "0.14.27"
 edition                 = "2024"
 
 [dependencies]
diff --git a/common/Cargo.toml b/common/Cargo.toml
index 4e7b22c..6357b19 100644
--- a/common/Cargo.toml
+++ b/common/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name                    = "lesavka_common"
-version                 = "0.14.26"
+version                 = "0.14.27"
 edition                 = "2024"
 build                   = "build.rs"
 
diff --git a/docs/operational-env.md b/docs/operational-env.md
index fce9896..4300f6c 100644
--- a/docs/operational-env.md
+++ b/docs/operational-env.md
@@ -221,6 +221,7 @@ Hardware-facing assumptions belong near the code that uses them; this file is th
 | `LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US` | server upstream playout override; shifts webcam-video presentation relative to the shared playout epoch |
 | `LESAVKA_UPLINK_CAMERA_PREVIEW` | client media capture/playback override |
 | `LESAVKA_UPLINK_MIC_LEVEL` | client media capture/playback override |
+| `LESAVKA_INSTALL_UVC_CODEC` | installer override; sets the persisted default UVC webcam codec in `/etc/lesavka/server.env` and `/etc/lesavka/uvc.env` |
 | `LESAVKA_USB_RECOVERY_` | USB recovery timing override |
 | `LESAVKA_USB_RECOVERY_CYCLE_WAIT_MS` | USB recovery timing override |
 | `LESAVKA_USB_RECOVERY_FINAL_WAIT_MS` | USB recovery timing override |
diff --git a/scripts/install/server.sh b/scripts/install/server.sh
index 244e1e3..da5e028 100755
--- a/scripts/install/server.sh
+++ b/scripts/install/server.sh
@@ -10,6 +10,7 @@ export TMPDIR=${TMPDIR:-/var/tmp}
 REF=${LESAVKA_REF:-master}        # fallback
 REPO_URL=${LESAVKA_REPO_URL:-}
 USER_HOME=$(getent passwd "$ORIG_USER" | cut -d: -f6)
+INSTALL_UVC_CODEC=${LESAVKA_INSTALL_UVC_CODEC:-mjpeg}
 
 manifest_package_version() {
   local manifest=$1
@@ -32,7 +33,7 @@ LESAVKA_UVC_FPS=${LESAVKA_UVC_FPS:-20}
 LESAVKA_UVC_INTERVAL=${LESAVKA_UVC_INTERVAL:-500000}
 LESAVKA_UVC_WIDTH=${LESAVKA_UVC_WIDTH:-640}
 LESAVKA_UVC_HEIGHT=${LESAVKA_UVC_HEIGHT:-480}
-LESAVKA_UVC_CODEC=${LESAVKA_UVC_CODEC:-mjpeg}
+LESAVKA_UVC_CODEC=${INSTALL_UVC_CODEC}
 LESAVKA_UVC_BLOCKING=${LESAVKA_UVC_BLOCKING:-1}
 LESAVKA_UVC_MAXBURST=${LESAVKA_UVC_MAXBURST:-0}
 EOF
@@ -567,7 +568,7 @@ fi
   printf 'LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US=%s\n' "${LESAVKA_UPSTREAM_VIDEO_PLAYOUT_OFFSET_US:-0}"
   printf 'LESAVKA_UPSTREAM_PAIR_SLACK_US=%s\n' "${LESAVKA_UPSTREAM_PAIR_SLACK_US:-20000}"
   printf 'LESAVKA_UPSTREAM_STALE_DROP_MS=%s\n' "${LESAVKA_UPSTREAM_STALE_DROP_MS:-80}"
-  printf 'LESAVKA_UVC_CODEC=%s\n' "${LESAVKA_UVC_CODEC:-mjpeg}"
+  printf 'LESAVKA_UVC_CODEC=%s\n' "${INSTALL_UVC_CODEC}"
 } | sudo tee /etc/lesavka/server.env >/dev/null
 
 UVC_ENV_TMP=$(mktemp)
@@ -655,7 +656,7 @@ if [[ -n ${LESAVKA_ALLOW_GADGET_RESET:-} ]] || [[ "$FORCE_GADGET_REBUILD" == "1"
     LESAVKA_DETACH_CLEAR_UDC=1 \
     LESAVKA_RELOAD_UVCVIDEO=1 \
     LESAVKA_UVC_FALLBACK=0 \
-    LESAVKA_UVC_CODEC="${LESAVKA_UVC_CODEC:-mjpeg}" \
+    LESAVKA_UVC_CODEC="${INSTALL_UVC_CODEC}" \
     /usr/local/bin/lesavka-core.sh
   sudo systemctl restart lesavka-core
   echo "✅  lesavka-core installed and restarted..."
diff --git a/server/Cargo.toml b/server/Cargo.toml
index ebae3fd..5cafee2 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -10,7 +10,7 @@ bench                   = false
 
 [package]
 name                    = "lesavka_server"
-version                 = "0.14.26"
+version                 = "0.14.27"
 edition                 = "2024"
 autobins                = false
 
diff --git a/testing/tests/server_install_script_contract.rs b/testing/tests/server_install_script_contract.rs
index becba18..91f7466 100644
--- a/testing/tests/server_install_script_contract.rs
+++ b/testing/tests/server_install_script_contract.rs
@@ -39,6 +39,7 @@ fn server_install_pins_hdmi_camera_and_display_defaults() {
     assert!(SERVER_INSTALL.contains("${LESAVKA_CAM_HEIGHT:-1080}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_CAM_FPS:-30}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_INSTALL_CAM_OUTPUT:-uvc}"));
+    assert!(SERVER_INSTALL.contains("${LESAVKA_INSTALL_UVC_CODEC:-mjpeg}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_HDMI_WIDTH:-1920}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_HDMI_HEIGHT:-1080}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_HDMI_SINK:-fbdevsink}"));
@@ -49,7 +50,10 @@ fn server_install_pins_hdmi_camera_and_display_defaults() {
     assert!(SERVER_INSTALL.contains("${LESAVKA_UVC_INTERVAL:-500000}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_UVC_WIDTH:-640}"));
     assert!(SERVER_INSTALL.contains("${LESAVKA_UVC_HEIGHT:-480}"));
-    assert!(SERVER_INSTALL.contains("${LESAVKA_UVC_CODEC:-mjpeg}"));
+    assert!(
+        !SERVER_INSTALL.contains("LESAVKA_UVC_CODEC=${LESAVKA_UVC_CODEC:-mjpeg}"),
+        "install script should not let ambient LESAVKA_UVC_CODEC leak into persisted defaults"
+    );
     assert!(
         SERVER_INSTALL.contains("EnvironmentFile=-/etc/lesavka/uvc.env"),
         "install script should feed live UVC runtime settings into services"