diff --git a/tools/ci/pre-push.sh b/tools/ci/pre-push.sh
index c6364234..fa06a7f2 100755
--- a/tools/ci/pre-push.sh
+++ b/tools/ci/pre-push.sh
@@ -59,6 +59,7 @@ tree_checks() {
   run "shell inside .github/workflows parses (bash -n, the PowerShell 5.1 rule)" node tools/ci/check-workflow-shell.mjs
   run "PowerShell drive-reference check (\$name: in a double-quoted string)"    bash tools/ci/ps-drive-ref-check.sh
   run "copied sources are re-stamped before a build"                           bash tools/ci/copied-sources-check.sh
+  run "the prover pair is built from the pinned node's exec types (prover-pair-check)"      bash -c 'bash tools/ci/prover-pair-check.sh --self-test && bash tools/ci/prover-pair-check.sh'
   run "override params files parse with no duplicate key"                      bash tools/ci/override-json-check.sh
   run "second-engine playbooks log to a file and end their tree (C35)"         bash tools/ci/second-engine-check.sh
   run "no playbook quits, pauses or resumes the installed app"                 bash -c 'bash tools/ci/playbook-quit-check.sh --self-test && bash tools/ci/playbook-quit-check.sh'
diff --git a/tools/ci/prover-pair-check.sh b/tools/ci/prover-pair-check.sh
new file mode 100755
index 00000000..f9222a80
--- /dev/null
+++ b/tools/ci/prover-pair-check.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+# A release's prover pair is built from the same execution types as its node (7 October 2026, main's rule, the class of the
+# igneum-pow pairing rule): the fleet's 14 standing provers cut a different state root from the 0.3.17 node on every segment
+# because their pair came from another tree. The proving crate depends on vendor/igneum-node-exec/igneum/evm-types (and revm);
+# the node ships from the fork commit in packaging/windows/node-source.pin. This check fails when the evm-types tree the prover
+# is built against differs from the evm-types tree of the pinned node commit.
+#
+#   tools/ci/prover-pair-check.sh              compare (needs the fork worktree under vendor/ that holds the pinned commit)
+#   tools/ci/prover-pair-check.sh --self-test  the comparison on two known trees
+set -euo pipefail
+HERE="$(cd "$(dirname "$0")/../.." && pwd)"
+tree_of() { git -C "$1" rev-parse "$2:igneum/evm-types" 2>/dev/null || true; }
+if [ "${1:-}" = "--self-test" ]; then
+  d=$(mktemp -d); trap 'rm -rf "$d"' EXIT
+  git -C "$d" init -q; mkdir -p "$d/igneum/evm-types"; echo a > "$d/igneum/evm-types/lib.rs"; git -C "$d" add -A; git -C "$d" -c user.name=t -c user.email=t@t commit -qm one
+  one=$(git -C "$d" rev-parse HEAD); echo b > "$d/igneum/evm-types/lib.rs"; git -C "$d" add -A; git -C "$d" -c user.name=t -c user.email=t@t commit -qm two; two=$(git -C "$d" rev-parse HEAD)
+  [ "$(tree_of "$d" "$one")" != "$(tree_of "$d" "$two")" ] || { echo "prover-pair: self-test FAILED (two different trees read equal)"; exit 1; }
+  [ "$(tree_of "$d" "$one")" = "$(tree_of "$d" "$one")" ] || { echo "prover-pair: self-test FAILED"; exit 1; }
+  echo "prover-pair: self-test ok"; exit 0
+fi
+pin_file="$HERE/packaging/windows/node-source.pin"
+[ -f "$pin_file" ] || { echo "prover-pair: no $pin_file (nothing pinned; skipped)"; exit 0; }
+pin=$(head -1 "$pin_file" | awk '{print $1}')
+exec_wt="$HERE/vendor/igneum-node-exec"
+[ -d "$exec_wt" ] || { echo "prover-pair: no vendor/igneum-node-exec worktree (the prover's exec types); skipped"; exit 0; }
+prover_tree=$(tree_of "$exec_wt" HEAD)
+node_tree=""
+for wt in "$HERE"/vendor/igneum-node-*; do
+  [ -d "$wt" ] || continue
+  t=$(tree_of "$wt" "$pin"); [ -n "$t" ] && { node_tree="$t"; break; }
+done
+[ -n "$node_tree" ] || { echo "prover-pair: the pinned node commit ${pin:0:8} is in no fork worktree under vendor/; cannot compare (skipped)"; exit 0; }
+if [ "$prover_tree" != "$node_tree" ]; then
+  echo "prover-pair: FAIL: the prover's exec types (vendor/igneum-node-exec $(git -C "$exec_wt" rev-parse --short=8 HEAD), evm-types tree ${prover_tree:0:12}) differ from the pinned node's (${pin:0:8}, tree ${node_tree:0:12}); rebuild the prover pair against the node's tree before the inputs push and the DMG"
+  exit 1
+fi
+echo "prover-pair: ok: the prover's exec types (evm-types tree ${prover_tree:0:12}) equal the pinned node's (${pin:0:8})"