diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9b1e8106e..194d359c5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -593,7 +593,12 @@ jobs:
           terraform_version: 1.10.5
 
       - name: Terraform Format Check
-        run: terraform fmt -check -recursive terraform/
+        # Must cover every SCAN_ROOTS entry in scripts/check-gcp-secret-scope.sh,
+        # whose block tracking was written against fmt layout (#150). The
+        # guard's self-test fails if a scan root has no line here.
+        run: |
+          terraform fmt -check -recursive terraform/
+          terraform fmt -check -recursive iac/
 
       - name: Test Azure federation identity guards
         if: matrix.cloud == 'azure'
diff --git a/scripts/check-gcp-secret-scope.sh b/scripts/check-gcp-secret-scope.sh
index 3b25f4bc5..ece200f7d 100755
--- a/scripts/check-gcp-secret-scope.sh
+++ b/scripts/check-gcp-secret-scope.sh
@@ -47,6 +47,17 @@
 # which role it becomes. Refusing it is the fail-closed answer; the fix is to
 # write the role name out.
 #
+# The one shape that breaks the premise above is refused outright (issue #150):
+# an authoritative policy (`google_project_iam_policy`, `google_folder_iam_policy`,
+# `google_organization_iam_policy`) and the `data "google_iam_policy"` source
+# that builds policy_data for one. policy_data can be read with file() from a
+# JSON file the guard does not scan, or handed in through a variable or module
+# output, so the role it grants need never appear as text here. It is also the
+# most dangerous shape: it REPLACES the scope's whole IAM policy. Any
+# non-comment mention of one of those type names exits 2 before the scan runs,
+# and no waiver applies. Correlating policy_data with its source is the work to
+# do if one is ever genuinely needed.
+#
 # WAIVERS. A deliberate scope-wide Secret Manager grant is permitted by a comment
 # on the line DIRECTLY above the mention it excuses, with a reason:
 #
@@ -61,7 +72,8 @@
 #
 # Exit 0 = no un-waived Secret Manager mention and no plan-time role name found.
 # Exit 1 = at least one found; each is printed to stderr.
-# Exit 2 = usage error, or a file this guard cannot read (JSON encoding).
+# Exit 2 = usage error, a file this guard cannot read (JSON encoding), or an
+#          authoritative IAM policy it cannot analyze (see above).
 #
 # LIMITATIONS. This is a textual guard, not a policy engine.
 #   - Values supplied from OUTSIDE the scanned tree are out of reach: `-var` on
@@ -75,6 +87,17 @@
 #   - The Terraform JSON encoding (`.tf.json`, `.tfvars.json`) is not parsed.
 #     Rather than report such a file as clean, the guard exits 2 if it finds one.
 #     None exist today.
+#   - The authoritative-policy shape (`google_{project,folder,organization}
+#     _iam_policy`, `data "google_iam_policy"`) is REJECTED with exit 2, not
+#     analyzed (issue #150). That includes a `google_iam_policy` data source
+#     feeding a per-secret `_iam_policy`, since the guard cannot tell where
+#     policy_data goes. None exist today.
+#   - Block tracking (which decides the per-secret exemption) counts braces and
+#     does not need `terraform fmt` layout to stay closed, but CI also runs
+#     `terraform fmt -check` over every SCAN_ROOTS entry, so unformatted code
+#     cannot land in the first place.
+#   - Resources inside modules sourced from outside the tree (registry, git)
+#     are not scanned.
 #
 # Usage:
 #   scripts/check-gcp-secret-scope.sh              # scan the default roots
@@ -148,6 +171,42 @@ if [[ ${#files[@]} -eq 0 ]]; then
   exit 2
 fi
 
+# Fail closed on the authoritative-policy shape (issue #150; see the header).
+# Matches the type name as a token anywhere in a non-comment line, so a quoted
+# or bare block label, any indentation, and references (`data.google_iam_policy.
+# x`, `moved`, `import`) are all caught. Heredoc bodies and descriptions are
+# not exempt here: over-reporting a name that should not be in the tree at all
+# is the safe direction.
+unsupported=$(
+  awk '
+    /^[[:space:]]*(#|\/\/)/ { next }
+    /(^|[^A-Za-z0-9_])google_(project|folder|organization)_iam_policy([^A-Za-z0-9_]|$)/ ||
+    /(^|[^A-Za-z0-9_])google_iam_policy([^A-Za-z0-9_]|$)/ {
+      t = $0
+      sub(/^[[:space:]]+/, "", t)
+      printf "%s:%d: %s\n", FILENAME, FNR, t
+    }
+  ' "${files[@]}"
+)
+if [[ -n "$unsupported" ]]; then
+  {
+    echo "ERROR: this guard cannot analyze an authoritative IAM policy, and will not"
+    echo "       report one as clean (issue #150). Found:"
+    while IFS= read -r finding; do
+      printf '         %s\n' "$finding"
+    done <<<"$unsupported"
+    echo ""
+    echo "       google_{project,folder,organization}_iam_policy replaces the scope's"
+    echo "       whole IAM policy with policy_data, which may come from file(), a"
+    echo "       variable or a module output the guard cannot follow, so it cannot say"
+    echo "       which roles are granted. Use google_{project,folder,organization}"
+    echo "       _iam_member for non-secret roles and google_secret_manager_secret"
+    echo "       _iam_member for secrets, or extend the guard to correlate policy_data"
+    echo "       with its source before adding one."
+  } >&2
+  exit 2
+fi
+
 # Line scanner. Portable awk only (CI runs mawk, macOS runs BWK awk): no gawk
 # extensions, no regex intervals, braces matched via bracket expressions.
 #
diff --git a/scripts/test-gcp-secret-scope.sh b/scripts/test-gcp-secret-scope.sh
index 62bfe7ab1..8790f12b1 100755
--- a/scripts/test-gcp-secret-scope.sh
+++ b/scripts/test-gcp-secret-scope.sh
@@ -90,13 +90,15 @@ run_case "role passed as a module argument exits 1" 1 \
 run_case "role supplied by a tfvars file exits 1" 1 \
   "${FIXTURES}/roles.tfvars.fixture"
 
-run_case "dynamic binding in google_iam_policy over a local exits 1" 1 \
+# These three carried the authoritative-policy shape and exited 1 through the
+# role text alone. Since issue #150 that shape is refused outright (exit 2).
+run_case "dynamic binding in google_iam_policy over a local exits 2 (#150)" 2 \
   "${FIXTURES}/dynamic-iam-policy.tf.fixture"
 
-run_case "literal role in google_iam_policy data block exits 1" 1 \
+run_case "literal role in google_iam_policy data block exits 2 (#150)" 2 \
   "${FIXTURES}/iam-policy-data.tf.fixture"
 
-run_case "JSON heredoc policy_data on google_project_iam_policy exits 1" 1 \
+run_case "JSON heredoc policy_data on google_project_iam_policy exits 2 (#150)" 2 \
   "${FIXTURES}/policy-heredoc.tf.fixture"
 
 run_case "custom role carrying secretmanager.* permissions exits 1" 1 \
@@ -105,6 +107,42 @@ run_case "custom role carrying secretmanager.* permissions exits 1" 1 \
 run_case "block not laid out the way terraform fmt does exits 1" 1 \
   "${FIXTURES}/unformatted-block.tf.fixture"
 
+# Issue #150, part 1: the authoritative-policy shape is refused (exit 2) rather
+# than analyzed. Each of the first six exited 0 before #150, because the roles
+# it grants never appear as `secretmanager` text in a scanned file.
+run_case "google_project_iam_policy fed by file() exits 2 (#150)" 2 \
+  "${FIXTURES}/project-iam-policy-file.tf.fixture"
+
+run_case "google_folder_iam_policy fed by a variable exits 2 (#150)" 2 \
+  "${FIXTURES}/folder-iam-policy.tf.fixture"
+
+run_case "google_organization_iam_policy fed by jsonencode exits 2 (#150)" 2 \
+  "${FIXTURES}/org-iam-policy.tf.fixture"
+
+run_case "google_iam_policy data source exported as an output exits 2 (#150)" 2 \
+  "${FIXTURES}/iam-policy-data-output.tf.fixture"
+
+run_case "authoritative policy with bare block labels exits 2 (#150)" 2 \
+  "${FIXTURES}/iam-policy-unquoted-labels.tf.fixture"
+
+run_case "authoritative policy with a column-0 body exits 2 (#150)" 2 \
+  "${FIXTURES}/iam-policy-unindented.tf.fixture"
+
+run_case "rejected shape alongside a clean file still exits 2 (#150)" 2 \
+  "${FIXTURES}/clean.tf.fixture" "${FIXTURES}/project-iam-policy-file.tf.fixture"
+
+# Negative direction: lookalike type names and comments are not refused.
+run_case "lookalike IAM policy types and comments exit 0 (#150)" 0 \
+  "${FIXTURES}/iam-policy-lookalikes.tf.fixture"
+
+# Issue #150, part 2: a body laid out in column 0 must not end a block early
+# enough to drop a role, nor carry the per-secret exemption onward.
+run_case "scope-wide grant with a column-0 body exits 1 (#150)" 1 \
+  "${FIXTURES}/unindented-body.tf.fixture"
+
+run_case "column-0 per-secret body does not leak its exemption (#150)" 1 \
+  "${FIXTURES}/per-secret-unindented-body.tf.fixture"
+
 # Fail closed on role names the scanner cannot resolve.
 run_case "role assembled by interpolation exits 1" 1 \
   "${FIXTURES}/interpolated-role.tf.fixture"
@@ -170,6 +208,36 @@ fi
 run_case "ci-cd-permissions deploy SA grant fails without its waiver" 1 \
   "${WORK}/service_account.tf"
 
+# policy-heredoc now exits 2 on its resource type alone, which would hide a
+# regression in how heredoc bodies are scanned. Retyped to a per-secret
+# _iam_policy (not refused), the role inside the JSON heredoc must still be
+# reported: only a plain `role = "roles/secretmanager.X"` line is exempt.
+sed 's/google_project_iam_policy/google_secret_manager_secret_iam_policy/g' \
+  "${FIXTURES}/policy-heredoc.tf.fixture" > "${WORK}/per-secret-heredoc.tf"
+run_case "JSON heredoc role on a per-secret _iam_policy exits 1" 1 \
+  "${WORK}/per-secret-heredoc.tf"
+
+# Issue #150, part 2: the guard's block tracking was written against
+# `terraform fmt` layout, so CI must run `terraform fmt -check -recursive` over
+# every root the guard scans. Read the roots from the guard itself so adding one without a fmt gate
+# fails here.
+CI_YML="${REPO_ROOT}/.github/workflows/ci.yml"
+# shellcheck disable=SC2016  # ${REPO_ROOT} is matched literally, not expanded.
+roots=$(sed -n '/^SCAN_ROOTS=(/,/^)/s|^ *"\${REPO_ROOT}/\([^"]*\)"$|\1|p' "$CHECK")
+if [[ -z "$roots" ]]; then
+  echo "FAIL: could not read SCAN_ROOTS from $CHECK"
+  (( fail++ )) || true
+fi
+for root in $roots; do
+  if grep -Eq "^[[:space:]]*(run:[[:space:]]*)?terraform fmt -check -recursive ${root}/?[[:space:]]*$" "$CI_YML"; then
+    echo "PASS: CI runs terraform fmt -check over scan root ${root}/"
+    (( pass++ )) || true
+  else
+    echo "FAIL: CI has no 'terraform fmt -check -recursive ${root}/' step for scan root ${root}/"
+    (( fail++ )) || true
+  fi
+done
+
 # Default-root discovery: run a copy of the guard from a throwaway tree laid out
 # like the repo, so the cases below exercise which files it COLLECTS, not only
 # how it scans files it is handed.
diff --git a/scripts/testdata/gcp-secret-scope/dynamic-iam-policy.tf.fixture b/scripts/testdata/gcp-secret-scope/dynamic-iam-policy.tf.fixture
index 314bbfe8f..59d69fed8 100644
--- a/scripts/testdata/gcp-secret-scope/dynamic-iam-policy.tf.fixture
+++ b/scripts/testdata/gcp-secret-scope/dynamic-iam-policy.tf.fixture
@@ -1,6 +1,7 @@
 # Fixture: an authoritative project policy built from a `google_iam_policy` data
 # source whose bindings come from a `dynamic` block over a local list. Neither
-# the data block nor the policy resource carries the literal. Must exit 1.
+# the data block nor the policy resource carries the literal. Since issue #150
+# the guard refuses the authoritative-policy shape outright. Must exit 2.
 
 locals {
   policy_roles = ["roles/viewer", "roles/secretmanager.secretAccessor"]
diff --git a/scripts/testdata/gcp-secret-scope/folder-iam-policy.tf.fixture b/scripts/testdata/gcp-secret-scope/folder-iam-policy.tf.fixture
new file mode 100644
index 000000000..c48b8f50f
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/folder-iam-policy.tf.fixture
@@ -0,0 +1,11 @@
+# Fixture (issue #150): an authoritative folder policy whose policy_data comes
+# from a variable with no in-tree default. Must exit 2.
+
+variable "folder_policy_data" {
+  type = string
+}
+
+resource "google_folder_iam_policy" "folder" {
+  folder      = var.folder_id
+  policy_data = var.folder_policy_data
+}
diff --git a/scripts/testdata/gcp-secret-scope/iam-policy-data-output.tf.fixture b/scripts/testdata/gcp-secret-scope/iam-policy-data-output.tf.fixture
new file mode 100644
index 000000000..27b8cefca
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/iam-policy-data-output.tf.fixture
@@ -0,0 +1,16 @@
+# Fixture (issue #150): a `google_iam_policy` data source on its own, exported as
+# a module output. Its policy_data can be applied by a scope-wide policy
+# resource in whichever configuration consumes the output, which the guard
+# cannot follow. The role comes from a variable with no in-tree default.
+# Must exit 2.
+
+data "google_iam_policy" "workload" {
+  binding {
+    role    = var.workload_role
+    members = ["serviceAccount:workload@example.iam.gserviceaccount.com"]
+  }
+}
+
+output "workload_policy_data" {
+  value = data.google_iam_policy.workload.policy_data
+}
diff --git a/scripts/testdata/gcp-secret-scope/iam-policy-data.tf.fixture b/scripts/testdata/gcp-secret-scope/iam-policy-data.tf.fixture
index 3d09906cf..29eede8cb 100644
--- a/scripts/testdata/gcp-secret-scope/iam-policy-data.tf.fixture
+++ b/scripts/testdata/gcp-secret-scope/iam-policy-data.tf.fixture
@@ -1,6 +1,7 @@
 # Fixture: a literal role inside a `google_iam_policy` data block feeding
 # google_project_iam_policy. The data block is not a scope-wide IAM resource, so
-# a scanner keyed on resource type misses it. Must exit 1.
+# a scanner keyed on resource type misses it. Since issue #150 the guard refuses
+# the authoritative-policy shape outright rather than analyzing it. Must exit 2.
 
 data "google_iam_policy" "project" {
   binding {
diff --git a/scripts/testdata/gcp-secret-scope/iam-policy-lookalikes.tf.fixture b/scripts/testdata/gcp-secret-scope/iam-policy-lookalikes.tf.fixture
new file mode 100644
index 000000000..cb1d01eb0
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/iam-policy-lookalikes.tf.fixture
@@ -0,0 +1,28 @@
+# Fixture (issue #150, negative direction): types whose names share words with
+# the rejected authoritative-policy types, and a comment naming one, must not
+# be rejected. Only google_{project,folder,organization}_iam_policy and
+# google_iam_policy are. Must exit 0.
+
+# A comment may say google_project_iam_policy or data "google_iam_policy".
+// So may a // comment: google_organization_iam_policy.
+
+resource "google_secret_manager_secret_iam_policy" "secret" {
+  project     = var.project_id
+  secret_id   = var.secret_id
+  policy_data = var.secret_policy_data
+}
+
+resource "google_storage_bucket_iam_policy" "bucket" {
+  bucket      = var.bucket_name
+  policy_data = var.bucket_policy_data
+}
+
+resource "google_project_iam_member" "viewer" {
+  project = var.project_id
+  role    = "roles/viewer"
+  member  = "serviceAccount:workload@example.iam.gserviceaccount.com"
+}
+
+locals {
+  my_google_iam_policy_name = "not-a-data-source"
+}
diff --git a/scripts/testdata/gcp-secret-scope/iam-policy-unindented.tf.fixture b/scripts/testdata/gcp-secret-scope/iam-policy-unindented.tf.fixture
new file mode 100644
index 000000000..b33294e99
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/iam-policy-unindented.tf.fixture
@@ -0,0 +1,7 @@
+# Fixture (issue #150): an authoritative project policy whose body starts in
+# column 0, the layout `terraform fmt` would rewrite. Must exit 2.
+
+resource "google_project_iam_policy" "project" {
+project = var.project_id
+policy_data = var.project_policy_data
+}
diff --git a/scripts/testdata/gcp-secret-scope/iam-policy-unquoted-labels.tf.fixture b/scripts/testdata/gcp-secret-scope/iam-policy-unquoted-labels.tf.fixture
new file mode 100644
index 000000000..b39efb926
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/iam-policy-unquoted-labels.tf.fixture
@@ -0,0 +1,8 @@
+# Fixture (issue #150): HCL accepts bare identifiers as block labels, so the
+# resource type need not be quoted. Matching only `resource "google_..._policy"`
+# would miss this. Must exit 2.
+
+resource google_project_iam_policy project {
+  project     = var.project_id
+  policy_data = var.project_policy_data
+}
diff --git a/scripts/testdata/gcp-secret-scope/org-iam-policy.tf.fixture b/scripts/testdata/gcp-secret-scope/org-iam-policy.tf.fixture
new file mode 100644
index 000000000..8b4faedb2
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/org-iam-policy.tf.fixture
@@ -0,0 +1,13 @@
+# Fixture (issue #150): an authoritative organization policy built with
+# jsonencode() from a role supplied by a variable with no in-tree default.
+# Must exit 2.
+
+resource "google_organization_iam_policy" "org" {
+  org_id = var.org_id
+  policy_data = jsonencode({
+    bindings = [{
+      role    = var.org_role
+      members = ["serviceAccount:workload@example.iam.gserviceaccount.com"]
+    }]
+  })
+}
diff --git a/scripts/testdata/gcp-secret-scope/per-secret-unindented-body.tf.fixture b/scripts/testdata/gcp-secret-scope/per-secret-unindented-body.tf.fixture
new file mode 100644
index 000000000..b5cd8c103
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/per-secret-unindented-body.tf.fixture
@@ -0,0 +1,20 @@
+# Fixture (issue #150): a per-secret binding whose body starts in column 0, with
+# a column-0 `}` closing a nested block before a second resource. The
+# per-secret exemption must not reach the project grant that follows, however
+# the closing braces are laid out. Must exit 1.
+
+resource "google_secret_manager_secret_iam_member" "unindented" {
+project   = var.project_id
+secret_id = var.secret_id
+condition {
+title      = "always"
+expression = "true"
+}
+role   = "roles/secretmanager.secretAccessor"
+member = "serviceAccount:workload@example.iam.gserviceaccount.com"
+}
+resource "google_project_iam_member" "after" {
+project = var.project_id
+role    = "roles/secretmanager.secretAccessor"
+member  = "serviceAccount:workload@example.iam.gserviceaccount.com"
+}
diff --git a/scripts/testdata/gcp-secret-scope/policy-heredoc.tf.fixture b/scripts/testdata/gcp-secret-scope/policy-heredoc.tf.fixture
index 901bbde48..4f6b869ea 100644
--- a/scripts/testdata/gcp-secret-scope/policy-heredoc.tf.fixture
+++ b/scripts/testdata/gcp-secret-scope/policy-heredoc.tf.fixture
@@ -1,6 +1,8 @@
 # Fixture: an authoritative project policy given as a JSON heredoc. The role is
 # heredoc text, and the JSON's own column-0 braces must not end the scan of it.
-# Must exit 1.
+# Since issue #150 the guard refuses google_project_iam_policy outright, so this
+# file exits 2; test-gcp-secret-scope.sh also runs a copy retyped to a per-secret
+# _iam_policy, which keeps the heredoc scan itself covered (exit 1).
 
 resource "google_project_iam_policy" "project" {
   project     = var.project_id
diff --git a/scripts/testdata/gcp-secret-scope/project-iam-policy-file.tf.fixture b/scripts/testdata/gcp-secret-scope/project-iam-policy-file.tf.fixture
new file mode 100644
index 000000000..66f774a5b
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/project-iam-policy-file.tf.fixture
@@ -0,0 +1,9 @@
+# Fixture (issue #150): an authoritative project policy whose policy_data is read
+# from a JSON file. The roles live in the .json file, which the guard does not
+# scan, so no `secretmanager` text appears anywhere it looks. The guard cannot
+# analyze this shape and must refuse it rather than report it clean. Must exit 2.
+
+resource "google_project_iam_policy" "project" {
+  project     = var.project_id
+  policy_data = file("${path.module}/project-policy.json")
+}
diff --git a/scripts/testdata/gcp-secret-scope/unindented-body.tf.fixture b/scripts/testdata/gcp-secret-scope/unindented-body.tf.fixture
new file mode 100644
index 000000000..ca5e85855
--- /dev/null
+++ b/scripts/testdata/gcp-secret-scope/unindented-body.tf.fixture
@@ -0,0 +1,14 @@
+# Fixture (issue #150): a scope-wide grant whose body starts in column 0. The
+# nested condition block's closing brace is in column 0 too, so a scanner that
+# treats `^}` as the end of the resource stops attributing lines to it before
+# the role. The role must still be reported. Must exit 1.
+
+resource "google_project_iam_member" "unindented" {
+project = var.project_id
+condition {
+title      = "always"
+expression = "true"
+}
+role   = "roles/secretmanager.secretAccessor"
+member = "serviceAccount:workload@example.iam.gserviceaccount.com"
+}