diff --git a/tagcmp_test.go b/tagcmp_test.go
index 87612bf..279df98 100644
--- a/tagcmp_test.go
+++ b/tagcmp_test.go
@@ -886,6 +886,52 @@ func TestDeltaString(t *testing.T) {
 	}
 }
 
+func TestIsUpgradeCompatible(t *testing.T) {
+	testsTrue := [][]string{
+		{"22-fpm", "22-fpm"},
+		{"22-fpm", "22.0-fpm"},
+		{"22-fpm", "22.0.0-fpm"},
+		{"22-fpm", "22.2.0-fpm"},
+		{"22-fpm", "22.0.0-fpm"},
+		{"22.2-fpm", "22.2-fpm"},
+		{"22.2-fpm", "22.2.0-fpm"},
+		{"22.2.2-fpm", "22.2.2-fpm"},
+	}
+	testsFalse := [][]string{
+		{"22-fpm", "22-alpine"},
+		{"22-fpm", "23-fpm"},
+		{"22-fpm", "21-fpm"},
+		{"22.2-fpm", "22.0.2-fpm"},
+		{"22.2.0-fpm", "22.2.2-fpm"},
+	}
+	for _, test := range testsTrue {
+		pin, err := tagcmp.Parse(test[0])
+		if err != nil {
+			t.Error(err)
+		}
+		upTag, err := tagcmp.Parse(test[1])
+		if err != nil {
+			t.Error(err)
+		}
+		if !pin.IsUpgradeCompatible(upTag) {
+			t.Errorf("pin %s should be upgradable to %s but returned false", test[0], test[1])
+		}
+	}
+	for _, test := range testsFalse {
+		pin, err := tagcmp.Parse(test[0])
+		if err != nil {
+			t.Error(err)
+		}
+		upTag, err := tagcmp.Parse(test[1])
+		if err != nil {
+			t.Error(err)
+		}
+		if pin.IsUpgradeCompatible(upTag) {
+			t.Errorf("pin %s should not be upgradable to %s but returned true", test[0], test[1])
+		}
+	}
+}
+
 func TestUpgradeDelta(t *testing.T) {
 	pairs := []struct {
 		t1        string