diff --git a/packages/xsnap/package.json b/packages/xsnap/package.json
index 3d67a418912..fd157a7be7d 100644
--- a/packages/xsnap/package.json
+++ b/packages/xsnap/package.json
@@ -16,6 +16,7 @@
     "build:env": "node src/build.js --show-env > build.env",
     "build:from-env": "{ cat build.env; echo node src/build.js; } | xargs env",
     "build": "yarn build:bin && yarn build:env",
+    "check-version": "xsnap_version=$(./scripts/get_xsnap_version.sh); if test \"${npm_package_version}\" != \"${xsnap_version}\"; then echo \"xsnap version mismatch; expected '${npm_package_version}', got '${xsnap_version}'\"; exit 1; fi",
     "postinstall": "npm run build:from-env",
     "clean": "rm -rf xsnap-native/xsnap/build",
     "lint": "run-s --continue-on-error lint:*",
@@ -56,6 +57,7 @@
     "moddable/xs/makefiles",
     "moddable/xs/platforms/*.h",
     "moddable/xs/sources",
+    "scripts",
     "src",
     "xsnap-native/xsnap/makefiles",
     "xsnap-native/xsnap/sources"
diff --git a/packages/xsnap/scripts/get_xsnap_version.sh b/packages/xsnap/scripts/get_xsnap_version.sh
new file mode 100755
index 00000000000..065c3724ab2
--- /dev/null
+++ b/packages/xsnap/scripts/get_xsnap_version.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+set -ueo pipefail
+
+# the xsnap binary lives in a platform-specific directory
+unameOut="$(uname -s)"
+case "${unameOut}" in
+  Linux*) platform=lin ;;
+  Darwin*) platform=mac ;;
+  *) platform=win ;;
+esac
+
+# extract the xsnap package version from the long version printed by xsnap-worker
+"./xsnap-native/xsnap/build/bin/${platform}/release/xsnap-worker" -v | sed -e 's/^xsnap \([^ ]*\) (XS [^)]*)$/\1/g'
diff --git a/repoconfig.sh b/repoconfig.sh
index 14194defb79..231093a2c66 100644
--- a/repoconfig.sh
+++ b/repoconfig.sh
@@ -4,7 +4,6 @@ NODEJS_VERSION=v16
 GOLANG_VERSION=1.20.3
 GOLANG_DIR=golang/cosmos
 GOLANG_DAEMON=$GOLANG_DIR/build/agd
-XSNAP_VERSION=agoric-upgrade-10
 
 # Args are major, minor and patch version numbers
 golang_version_check() {
@@ -12,7 +11,7 @@ golang_version_check() {
     [ "$1" -eq 1 ] && [ "$2" -eq 20 ] && [ "$3" -ge 2 ] && return 0
     [ "$1" -eq 1 ] && [ "$2" -ge 21 ] && return 0
     [ "$1" -ge 2 ] && return 0
-  } 2>/dev/null
+  } 2> /dev/null
   echo 1>&2 "need go version 1.20.2+, 1.21+, or 2+"
   return 1
 }
diff --git a/scripts/agd-builder.sh b/scripts/agd-builder.sh
index e55a4173c3e..39a1648dc44 100755
--- a/scripts/agd-builder.sh
+++ b/scripts/agd-builder.sh
@@ -219,21 +219,12 @@ $do_not_build || (
       echo "At least $src is newer than gyp bindings"
       (cd "$GOLANG_DIR" && lazy_yarn build:gyp)
     }
+
+    # check the built xsnap version against the package version it should be using
+    (cd "${thisdir}/../packages/xsnap" && npm run -s check-version) || exit 1
   fi
 )
 
-# the xsnap binary lives in a platform-specific directory
-unameOut="$(uname -s)"
-case "${unameOut}" in
-  Linux*) platform=lin ;;
-  Darwin*) platform=mac ;;
-  *) platform=win ;;
-esac
-
-# check the xsnap version against our baked-in notion of what version we should be using
-xsnap_version=$("${thisdir}/../packages/xsnap/xsnap-native/xsnap/build/bin/${platform}/release/xsnap-worker" -n)
-[[ "${xsnap_version}" == "${XSNAP_VERSION}" ]] || fatal "xsnap version mismatch; expected ${XSNAP_VERSION}, got ${xsnap_version}"
-
 if $only_build; then
   echo "Build complete." 1>&2
   exit 0