diff --git a/README.md b/README.md
index f3f3185..aa9d88d 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ It is designed for NixOS and for hosting on a private or public Gitea server wit
 ## What this project does
 
 - Builds a Proton-GE 10-34 / Wine 10 based compatibility tool for Elsword.
-- Uses Steam Linux Runtime 4 (`soldier`, appid `4183110`).
+- Uses Steam Linux Runtime Sniper (appid `1628350`), matching GE-Proton 10.
 - Builds DXVK for both x86 and x64.
 - Produces release archives that other users can install into Steam.
 - Disables optional extras that are known to be risky for game stability by default:
diff --git a/scripts/common.sh b/scripts/common.sh
index 547a59c..cbe8052 100755
--- a/scripts/common.sh
+++ b/scripts/common.sh
@@ -13,7 +13,7 @@ UPSTREAM_REPO="${UPSTREAM_REPO:-GloriousEggroll/proton-ge-custom}"
 ELSWORD_GE_VERSION="${ELSWORD_GE_VERSION:-10-34}"
 PROTON_TAG="${PROTON_TAG:-GE-Proton${ELSWORD_GE_VERSION}}"
 PROTON_ASSET="${PROTON_ASSET:-x86_64}"
-RUNTIME_APPID="${RUNTIME_APPID:-4183110}"
+RUNTIME_APPID="${RUNTIME_APPID:-1628350}"
 WINE_SERIES="${WINE_SERIES:-Wine 10}"
 DXVK_STABLE_TAG_DEFAULT="${DXVK_STABLE_TAG_DEFAULT:-latest}"
 DXVK_GIT_REF="${DXVK_GIT_REF:-origin/master}"
diff --git a/tests/common_test.sh b/tests/common_test.sh
index 95a0af3..9046b8c 100644
--- a/tests/common_test.sh
+++ b/tests/common_test.sh
@@ -12,6 +12,13 @@ fi
 
 printf 'Proton base is pinned to %s\n' "$PROTON_TAG"
 
+if [[ "$RUNTIME_APPID" != "1628350" ]]; then
+  printf 'expected Steam Runtime Sniper appid 1628350, got %s\n' "$RUNTIME_APPID" >&2
+  exit 1
+fi
+
+printf 'Proton 10 uses Steam Runtime Sniper\n'
+
 expected_tag="latest"
 actual_tag="$(dxvk_tag_for_variant stable)"