diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a729b7..7cae752 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,8 +29,10 @@ un-ignored `.verification/` or symlinks inside an untracked nested directory. A
 record written by 0.3.0 over such a tree goes stale here; it fails safe and is
 re-established by running again.
 
-Installation still pins the 0.3.0 runtime. The installer refuses a pin that is
-not already on `main`, so moving it to this release is a separate change.
+Installation (#11): `scripts/install-ladder.sh` and `scripts/check-install.sh`
+move their pin from `c86bf47`, the 0.3.0 runtime, to `819b7c2`, the commit that
+released 0.3.1 (#10). It had to be a separate change because the installer
+refuses a pin that is not already on `main`.
 
 ## 0.3.0 — contract `evidence-v3.2`
 
diff --git a/scripts/check-install.sh b/scripts/check-install.sh
index 77ebc18..ea779fd 100755
--- a/scripts/check-install.sh
+++ b/scripts/check-install.sh
@@ -8,7 +8,7 @@
 # repository with no verification policy.
 set -u
 
-PIN=c86bf47e70d7a3aa18c968011b487190e2becbea
+PIN=819b7c27cce400a40e3be75c8978351e1d7c82d4
 INV_SHA=282f21173aad9815a22a6ece35ad0fdd42653dd7a001dc6d85e6d51189aa5699
 CLONE=$HOME/src/verification-ladder
 LINK=$HOME/.claude/skills/verification-ladder
diff --git a/scripts/install-ladder.sh b/scripts/install-ladder.sh
index 4e4f684..ccaf8b4 100755
--- a/scripts/install-ladder.sh
+++ b/scripts/install-ladder.sh
@@ -10,7 +10,7 @@
 # to the checker it was reviewed with, for the same reason.
 set -u
 
-PIN=c86bf47e70d7a3aa18c968011b487190e2becbea
+PIN=819b7c27cce400a40e3be75c8978351e1d7c82d4
 REPO=https://github.com/Deep-Sixed/Verification-Ladder
 # sha256 of the invariant block in INSTALL.md at $PIN. Moving the pin without
 # revalidating this makes the installer fail closed rather than paste unknown
@@ -30,7 +30,7 @@ BOOTSTRAP_DIR=${XDG_DATA_HOME:-$HOME/.local/share}/verification-ladder
 # afterwards. Changing check-install.sh means changing this constant in the same
 # commit; a mismatch is refused rather than reported, because the checker is the
 # only thing that would have caught it.
-CHECKER_SHA=d7b922510547b8f9d856a897bd493a4a5db3785f2d2fd15fc259e542dcf6ce07
+CHECKER_SHA=3a460e1c996131f4ef4dca313d34e536a4c37ad3add11839ca632e6b3220219f
 SELF=$(readlink -f "$0" 2>/dev/null || echo "$0")
 SELF_DIR=$(dirname "$SELF")
 DO_CODEX=0; DRY=0; FORCE=0
diff --git a/tests/test_install_scripts.py b/tests/test_install_scripts.py
index 6a11d87..ed528ea 100644
--- a/tests/test_install_scripts.py
+++ b/tests/test_install_scripts.py
@@ -36,7 +36,7 @@
 REPO = Path(__file__).resolve().parents[1]
 INSTALLER = REPO / "scripts" / "install-ladder.sh"
 CHECKER = REPO / "scripts" / "check-install.sh"
-PIN = "c86bf47e70d7a3aa18c968011b487190e2becbea"
+PIN = "819b7c27cce400a40e3be75c8978351e1d7c82d4"
 ORIGIN = "https://github.com/Deep-Sixed/Verification-Ladder"
 
 
@@ -520,12 +520,17 @@ def test_the_pin_installs_the_hardened_release():
     therefore got none of that hardening, under the same contract identity as a
     build that had it. Hardcoded rather than compared with the working tree,
     because a future contract bump lands one PR before the pin can follow it.
+
+    It then pinned c86bf47, 0.3.0, which predates the input and state-boundary
+    fixes that 0.3.1 releases (#9): a scripted install kept the crash on
+    non-object JSON and the evidence-directory drift.
     """
-    assert PIN != "760977f69d6b74b9888be4c9cbb404f7726bea73"
+    assert PIN not in ("760977f69d6b74b9888be4c9cbb404f7726bea73", "c86bf47e70d7a3aa18c968011b487190e2becbea")
     runtime = _git("show", f"{PIN}:skills/verification-ladder/bin/verify.py", cwd=REPO).stdout
     assert 'COMPATIBILITY = "evidence-v3.2"' in runtime
-    assert 'VERSION = "0.3.0"' in runtime
+    assert 'VERSION = "0.3.1"' in runtime
     assert 'EVIDENCE_CONTRACT = "evidence"' in runtime, "the pinned runtime cannot read the adoption line"
+    assert "def _excluded(" in runtime, "the pinned runtime predates the evidence-directory prefix exclusion"
     for script in (INSTALLER, CHECKER):
         assert f"PIN={PIN}" in script.read_text(), f"{script.name} pins a different runtime"