diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 689425d..cd43f30 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -198,21 +198,46 @@ jobs:
             -e POSTGRES_DB=mcpg_test mcpg-ci-db
           if [ "${{ matrix.postgres }}" = "warehousepg-latest" ]; then
             DB_USER=gpadmin
-            # A single-node Greenplum-family coordinator+segment cluster
-            # takes much longer to initialize than a plain postgres
-            # container, so this lane gets a longer, coarser poll.
+          else
+            DB_USER=postgres
+          fi
+          echo "DB_USER=$DB_USER" >> "$GITHUB_ENV"
+          if [ "${{ matrix.postgres }}" = "warehousepg-latest" ]; then
+            # `woblerr/warehousepg` doesn't ship `pg_isready` on PATH — not
+            # documented upstream, confirmed by direct observation: every
+            # poll attempt with the pg_isready-based probe below fails with
+            # "executable file not found in $PATH", so it can never detect
+            # readiness and always burns its full poll budget (previously
+            # 90 * 4s = 360s) as dead time regardless of how fast the
+            # database actually comes up. Probe with `psql` instead — the
+            # runner's default client works here (see the "Install
+            # PostgreSQL client tools" step above, which skips a custom
+            # client for this lane on purpose) — connecting straight
+            # through the published port, the same path pytest itself
+            # uses. This also doubles as a stronger check than
+            # `pg_isready`: it only succeeds once the target database
+            # actually accepts queries, not just once the postmaster
+            # process is up. Keep the longer, coarser poll ceiling as a
+            # safety net — a single-node Greenplum-family
+            # coordinator+segment cluster can still legitimately take
+            # longer to initialize than a plain postgres container — but
+            # now the loop breaks as soon as it's actually ready instead
+            # of always waiting out the full ceiling.
             max_attempts=90
             sleep_secs=4
+            for _ in $(seq 1 "$max_attempts"); do
+              PGPASSWORD=postgres psql -h localhost -U "$DB_USER" -d mcpg_test -c 'SELECT 1' -q \
+                >/dev/null 2>&1 && break
+              sleep "$sleep_secs"
+            done
           else
-            DB_USER=postgres
             max_attempts=30
             sleep_secs=2
+            for _ in $(seq 1 "$max_attempts"); do
+              docker exec mcpg-db pg_isready -U "$DB_USER" && break
+              sleep "$sleep_secs"
+            done
           fi
-          echo "DB_USER=$DB_USER" >> "$GITHUB_ENV"
-          for _ in $(seq 1 "$max_attempts"); do
-            docker exec mcpg-db pg_isready -U "$DB_USER" && break
-            sleep "$sleep_secs"
-          done
       - name: Set up uv
         uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
         with:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b15a19..7700993 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,29 @@ adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
+
+- **Broken readiness probe on the `warehousepg-latest` CI lane was
+  burning ~6 minutes of dead time on every run.** The lane's readiness
+  poll used `docker exec mcpg-db pg_isready -U gpadmin`, but
+  `woblerr/warehousepg:7.4.1-WHPG` doesn't ship `pg_isready` on PATH —
+  every poll attempt failed with `exec: "pg_isready": executable file
+  not found in $PATH`, so the loop could never observe success and
+  always waited out its full 90 × 4s = 360s budget regardless of how
+  fast the database actually came up. Swapped the probe to `psql`
+  against the published port, the same path pytest itself uses —
+  identified from real `gh run view` timings (the "Start PostgreSQL"
+  step accounted for ~6-6.5 min of the lane's ~9-10 min total vs.
+  ~20-30s on every other PG version; the `pytest` step itself was
+  already the same duration as any other lane).
+
+### Security
+
+- **Bumped transitive `pip` 26.1.2 → 26.2.1 (PYSEC-2026-3721).**
+  `pip-audit`'s own `pip_api` dependency pulled in a `pip` version with
+  a known vulnerability, flagged by the local pre-commit hook's
+  dependency audit.
+
 ## [0.8.0] - 2026-08-19
 
 ### Security
diff --git a/uv.lock b/uv.lock
index fb52315..ea081a0 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1759,11 +1759,11 @@ wheels = [
 
 [[package]]
 name = "pip"
-version = "26.1.2"
+version = "26.2.1"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/01/91/47e7d486260f618783899587af63ccf7980fb60245c3e63dd4571c6b57ad/pip-26.1.2.tar.gz", hash = "sha256:f49cd134c61cf2fd75e0ce2676db03e4054504a5a4986d00f8299ae632dc4605", size = 1840799, upload-time = "2026-05-31T17:33:58.56Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/ae/15/4500e320e6b101ec3b719ae85b697d9940b6cda672bc555bd6016fc60c6f/pip-26.2.1.tar.gz", hash = "sha256:f6ad667e89a1fe78046c8f13232b247200f5258d7828f3f7883d660878e0813f", size = 1848877, upload-time = "2026-08-04T22:51:14.148Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/5d/95/6b5cb3461ea5673ba0995989746db58eb18b91b54dbf331e72f569540946/pip-26.1.2-py3-none-any.whl", hash = "sha256:382ff9f685ee3bc25864f820aa50505825f10f5458ffff07e30a6d96e5715cab", size = 1813144, upload-time = "2026-05-31T17:33:56.772Z" },
+    { url = "https://files.pythonhosted.org/packages/f3/6e/1736e5b4ae2b778ef2f81c47d797de9f891d4d8acb047a24ca37a60294dd/pip-26.2.1-py3-none-any.whl", hash = "sha256:71138adf1f4ca900cdb7d289c21b7494329f2332b6d85f0e1c42108c0384ed3e", size = 1816632, upload-time = "2026-08-04T22:51:12.472Z" },
 ]
 
 [[package]]