diff --git a/scripts/tests/identity-binding-v2-postgres-test.sh b/scripts/tests/identity-binding-v2-postgres-test.sh
index e6ffd017..4735b42d 100755
--- a/scripts/tests/identity-binding-v2-postgres-test.sh
+++ b/scripts/tests/identity-binding-v2-postgres-test.sh
@@ -46,17 +46,25 @@ docker run -d \
   postgres:16-alpine >/dev/null
 
 log "waiting for PostgreSQL readiness"
+postgres_ready="false"
 for _ in $(seq 1 60); do
-  if docker exec "${POSTGRES_CONTAINER}" \
+  pid_one_comm="$(
+    docker exec "${POSTGRES_CONTAINER}" \
+      cat /proc/1/comm 2>/dev/null || true
+  )"
+  if [[ "${pid_one_comm}" == "postgres" ]] \
+    && docker exec "${POSTGRES_CONTAINER}" \
       pg_isready -U "${POSTGRES_USER}" -d "${POSTGRES_DB}" \
       >/dev/null 2>&1; then
+    postgres_ready="true"
     break
   fi
   sleep 1
 done
-docker exec "${POSTGRES_CONTAINER}" \
-  pg_isready -U "${POSTGRES_USER}" -d "${POSTGRES_DB}" \
-  >/dev/null
+if [[ "${postgres_ready}" != "true" ]]; then
+  log "PostgreSQL did not become ready after entrypoint initialization"
+  exit 1
+fi
 log "PostgreSQL is ready"
 
 run_test() {