diff --git a/pkg/docker/boot_state_test.go b/pkg/docker/boot_state_test.go
new file mode 100644
index 000000000..587f6377d
--- /dev/null
+++ b/pkg/docker/boot_state_test.go
@@ -0,0 +1,81 @@
+package docker
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	statusDead       = "dead"
+	statusRemoving   = "removing"
+	statusExited     = "exited"
+	statusCreated    = "created"
+	statusPaused     = "paused"
+	statusRestarting = "restarting"
+)
+
+func TestFailedBootSentinel(t *testing.T) {
+	tests := []struct {
+		name         string
+		status       string
+		graceElapsed bool
+		wantSentinel error
+		wantNil      bool
+	}{
+		{"dead is terminal regardless of grace", statusDead, false, ErrContainerTerminal, false},
+		{"dead is terminal even after grace", statusDead, true, ErrContainerTerminal, false},
+		{
+			"removing is terminal regardless of grace",
+			statusRemoving,
+			false,
+			ErrContainerTerminal,
+			false,
+		},
+		{
+			"removing is terminal even after grace",
+			statusRemoving,
+			true,
+			ErrContainerTerminal,
+			false,
+		},
+		{"exited before grace is still booting", statusExited, false, nil, true},
+		{"exited after grace failed", statusExited, true, ErrContainerExited, false},
+		{"created before grace is still booting", statusCreated, false, nil, true},
+		{"created after grace failed", statusCreated, true, ErrContainerExited, false},
+		{"paused is not a terminal boot state", statusPaused, true, nil, true},
+		{"restarting is not a terminal boot state", statusRestarting, false, nil, true},
+		{"empty status is not a terminal boot state", "", true, nil, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := failedBootSentinel(tt.status, tt.graceElapsed)
+			if tt.wantNil {
+				assert.Nil(t, got, "expected nil sentinel for status %q", tt.status)
+				return
+			}
+			assert.ErrorIs(
+				t,
+				got,
+				tt.wantSentinel,
+				"status %q (grace=%v) should map to %v",
+				tt.status,
+				tt.graceElapsed,
+				tt.wantSentinel,
+			)
+		})
+	}
+}
+
+func TestFailedBootSentinel_TerminalNotConfusedWithExited(t *testing.T) {
+	terminal := failedBootSentinel(statusRemoving, false)
+	exited := failedBootSentinel(statusExited, true)
+
+	assert.ErrorIs(t, terminal, ErrContainerTerminal)
+	assert.NotErrorIs(t, terminal, ErrContainerExited,
+		"terminal states must not be reported as exited")
+	assert.ErrorIs(t, exited, ErrContainerExited)
+	assert.NotErrorIs(t, exited, ErrContainerTerminal,
+		"exited-after-grace must not be reported as terminal")
+}