diff --git a/internal/dispatch/gcf/provisioner.go b/internal/dispatch/gcf/provisioner.go
index f5b0a67dc..24eeacf96 100644
--- a/internal/dispatch/gcf/provisioner.go
+++ b/internal/dispatch/gcf/provisioner.go
@@ -410,6 +410,26 @@ func (p *Provisioner) EnsureOrgInMint(ctx context.Context, expectedURL string, o
 	}
 
 	allowedOrgs := trafficEnvVars["ALLOWED_ORGS"]
+
+	// Defense-in-depth: if ALLOWED_ORGS is empty but ROLE_APP_IDS has
+	// role-only entries, the mint has been bootstrapped and should have
+	// enrolled orgs. Empty ALLOWED_ORGS in this state indicates env var
+	// data loss (e.g., stale read from a diverged revision), not a first
+	// enrollment. Abort to prevent silently unenrolling all existing orgs.
+	if allowedOrgs == "" {
+		var roleAppIDMap map[string]string
+		if raw := trafficEnvVars["ROLE_APP_IDS"]; raw != "" {
+			_ = json.Unmarshal([]byte(raw), &roleAppIDMap)
+		}
+		roleOnly := mintcore.RoleOnlyAppIDs(roleAppIDMap)
+		if len(roleOnly) > 0 {
+			return fmt.Errorf(
+				"data inconsistency: ALLOWED_ORGS is empty but ROLE_APP_IDS has %d configured roles; "+
+					"this suggests env var data loss — run 'fullsend mint status --project=%s' to investigate",
+				len(roleOnly), p.cfg.ProjectID)
+		}
+	}
+
 	orgPresent := false
 	for _, o := range strings.Split(allowedOrgs, ",") {
 		if strings.EqualFold(strings.TrimSpace(o), org) {
diff --git a/internal/dispatch/gcf/provisioner_test.go b/internal/dispatch/gcf/provisioner_test.go
index ec3a233c6..55212f5ed 100644
--- a/internal/dispatch/gcf/provisioner_test.go
+++ b/internal/dispatch/gcf/provisioner_test.go
@@ -2416,6 +2416,66 @@ func TestEnsureOrgInMint_ProceedsOnFirstEnrollment(t *testing.T) {
 	assert.Equal(t, "new-org", fake.lastUpdateServiceEnvVars["ALLOWED_ORGS"])
 }
 
+func TestEnsureOrgInMint_DataInconsistencyGuard(t *testing.T) {
+	// When ALLOWED_ORGS is empty but ROLE_APP_IDS has role-only entries,
+	// the mint has been bootstrapped — empty ALLOWED_ORGS is data loss.
+	fake := newFakeGCFClient()
+	fake.functionInfo = &FunctionInfo{
+		URI:     "https://mint.example.com",
+		EnvVars: map[string]string{},
+	}
+	fake.trafficEnvVars = map[string]string{
+		"ALLOWED_ORGS": "",
+		"ROLE_APP_IDS": `{"coder":"111","reviewer":"222"}`,
+	}
+
+	p := NewProvisioner(Config{ProjectID: "proj1", Region: "us-central1"}, fake)
+	err := p.EnsureOrgInMint(context.Background(), "https://mint.example.com", "new-org")
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "data inconsistency")
+	assert.Contains(t, err.Error(), "2 configured roles")
+	assert.Contains(t, err.Error(), "proj1")
+	assert.NotContains(t, fake.calls, "UpdateServiceEnvVars")
+}
+
+func TestEnsureOrgInMint_DataInconsistencyGuard_NoRoleAppIDs(t *testing.T) {
+	// When ALLOWED_ORGS is empty and ROLE_APP_IDS is also empty,
+	// this is a genuine first enrollment — no error.
+	fake := newFakeGCFClient()
+	fake.functionInfo = &FunctionInfo{
+		URI:     "https://mint.example.com",
+		EnvVars: map[string]string{},
+	}
+	fake.trafficEnvVars = map[string]string{
+		"ALLOWED_ORGS": "",
+		"ROLE_APP_IDS": "",
+	}
+
+	p := NewProvisioner(Config{ProjectID: "proj1", Region: "us-central1"}, fake)
+	err := p.EnsureOrgInMint(context.Background(), "https://mint.example.com", "new-org")
+	require.NoError(t, err)
+	assert.Contains(t, fake.calls, "UpdateServiceEnvVars")
+}
+
+func TestEnsureOrgInMint_DataInconsistencyGuard_OnlyLegacyKeys(t *testing.T) {
+	// When ALLOWED_ORGS is empty and ROLE_APP_IDS has only legacy org/role
+	// keys (containing "/"), RoleOnlyAppIDs filters them out — no guard trigger.
+	fake := newFakeGCFClient()
+	fake.functionInfo = &FunctionInfo{
+		URI:     "https://mint.example.com",
+		EnvVars: map[string]string{},
+	}
+	fake.trafficEnvVars = map[string]string{
+		"ALLOWED_ORGS": "",
+		"ROLE_APP_IDS": `{"acme/coder":"111"}`,
+	}
+
+	p := NewProvisioner(Config{ProjectID: "proj1", Region: "us-central1"}, fake)
+	err := p.EnsureOrgInMint(context.Background(), "https://mint.example.com", "new-org")
+	require.NoError(t, err)
+	assert.Contains(t, fake.calls, "UpdateServiceEnvVars")
+}
+
 func TestRegisterPerRepoWIF_AddsNewRepo(t *testing.T) {
 	fake := newFakeGCFClient()
 	fake.functionInfo = &FunctionInfo{
@@ -2993,12 +3053,14 @@ func TestMarshalRoleAppIDs_SortsKeys(t *testing.T) {
 }
 
 func TestEnsureOrgInMint_DerivesAllowedRolesWhenEmpty(t *testing.T) {
+	// ALLOWED_ORGS populated, ALLOWED_ROLES empty — should derive roles
+	// from ROLE_APP_IDS and proceed.
 	fake := newFakeGCFClient()
 	fake.functionInfo = &FunctionInfo{
 		URI: "https://mint.example.com",
 	}
 	fake.trafficEnvVars = map[string]string{
-		"ALLOWED_ORGS": "",
+		"ALLOWED_ORGS": "existing-org",
 		"ROLE_APP_IDS": `{"coder":"100","triage":"200"}`,
 	}