diff --git a/cloud/bmaas/bmdb/backoff_test.go b/cloud/bmaas/bmdb/backoff_test.go
new file mode 100644
index 0000000..9d22f2a
--- /dev/null
+++ b/cloud/bmaas/bmdb/backoff_test.go
@@ -0,0 +1,61 @@
+package bmdb
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+// TestBackoffMath exercises the rules of Backoff.
+func TestBackoffMath(t *testing.T) {
+	for _, te := range []struct {
+		name     string
+		b        *Backoff
+		existing *existingBackoff
+		wantSecs []int64
+	}{
+		{"NoBackoffSet", nil, nil, []int64{1, 1, 1}},
+		{"EmptyBackoff", &Backoff{}, nil, []int64{1, 1, 1}},
+		{"SimpleBackoff", &Backoff{Initial: time.Minute}, nil, []int64{60, 60, 60}},
+		{"ExponentialWithMax",
+			&Backoff{Initial: time.Minute, Exponent: 1.1, Maximum: time.Minute * 2},
+			nil,
+			[]int64{60, 66, 73, 81, 90, 99, 109, 120, 120},
+		},
+
+		{"SimpleOverridePrevious",
+			&Backoff{Initial: time.Minute},
+			&existingBackoff{lastInterval: time.Second * 2},
+			[]int64{60, 60, 60},
+		},
+		{"ExponentialOverridePrevious",
+			&Backoff{Initial: time.Minute, Exponent: 2.0, Maximum: time.Minute * 2},
+			&existingBackoff{lastInterval: time.Second * 2},
+			[]int64{4, 8, 16, 32, 64, 120, 120},
+		},
+
+		{"ContinueExisting", nil, &existingBackoff{lastInterval: time.Minute}, []int64{60, 60, 60}},
+		{"ContinueExistingInvalid1", nil, &existingBackoff{lastInterval: 0}, []int64{1, 1, 1}},
+		{"ContinueExistingInvalid2", nil, &existingBackoff{lastInterval: time.Millisecond}, []int64{1, 1, 1}},
+
+		{"InvalidBackoff1", &Backoff{Exponent: 0.2}, nil, []int64{1, 1, 1}},
+		{"InvalidBackoff2", &Backoff{Maximum: time.Millisecond, Initial: time.Millisecond}, nil, []int64{1, 1, 1}},
+	} {
+		t.Run(te.name, func(t *testing.T) {
+			existing := te.existing
+
+			gotSecs := make([]int64, len(te.wantSecs))
+			for j := 0; j < len(te.wantSecs); j++ {
+				gotSecs[j] = te.b.next(existing)
+				existing = &existingBackoff{
+					lastInterval: time.Duration(gotSecs[j]) * time.Second,
+				}
+			}
+
+			if diff := cmp.Diff(te.wantSecs, gotSecs); diff != "" {
+				t.Errorf("Difference: %s", diff)
+			}
+		})
+	}
+}