diff --git a/collector/systemd_linux.go b/collector/systemd_linux.go
index 40c78438..a21cc3cb 100644
--- a/collector/systemd_linux.go
+++ b/collector/systemd_linux.go
@@ -83,10 +83,6 @@ type systemdCollector struct {
 
 var unitStatesName = []string{"active", "activating", "deactivating", "inactive", "failed"}
 
-type Manager interface {
-	GetManagerProperty(prop string) (string, error)
-}
-
 func init() {
 	registerCollector("systemd", defaultDisabled, NewSystemdCollector)
 }
@@ -437,8 +433,8 @@ func (c *systemdCollector) collectSummaryMetrics(ch chan<- prometheus.Metric, su
 	}
 }
 
-func (c *systemdCollector) collectSystemState(m Manager, ch chan<- prometheus.Metric) error {
-	systemState, err := m.GetManagerProperty("SystemState")
+func (c *systemdCollector) collectSystemState(conn *dbus.Conn, ch chan<- prometheus.Metric) error {
+	systemState, err := conn.GetManagerProperty("SystemState")
 	if err != nil {
 		return fmt.Errorf("couldn't get system state: %w", err)
 	}
@@ -506,8 +502,8 @@ func filterUnits(units []unit, includePattern, excludePattern *regexp.Regexp, lo
 	return filtered
 }
 
-func (c *systemdCollector) getSystemdVersion(m Manager) (float64, string) {
-	version, err := m.GetManagerProperty("Version")
+func (c *systemdCollector) getSystemdVersion(conn *dbus.Conn) (float64, string) {
+	version, err := conn.GetManagerProperty("Version")
 	if err != nil {
 		c.logger.Debug("Unable to get systemd version property, defaulting to 0")
 		return 0, ""
@@ -523,8 +519,8 @@ func (c *systemdCollector) getSystemdVersion(m Manager) (float64, string) {
 	return v, version
 }
 
-func (c *systemdCollector) getSystemdVirtualization(m Manager) string {
-	virt, err := m.GetManagerProperty("Virtualization")
+func (c *systemdCollector) getSystemdVirtualization(conn *dbus.Conn) string {
+	virt, err := conn.GetManagerProperty("Virtualization")
 	if err != nil {
 		c.logger.Debug("Could not get Virtualization property", "err", err)
 		return "unknown"
diff --git a/collector/systemd_linux_test.go b/collector/systemd_linux_test.go
index 0ac0bdad..1c290377 100644
--- a/collector/systemd_linux_test.go
+++ b/collector/systemd_linux_test.go
@@ -17,7 +17,6 @@
 package collector
 
 import (
-	"errors"
 	"io"
 	"log/slog"
 	"regexp"
@@ -138,60 +137,3 @@ func testSummaryHelper(t *testing.T, state string, actual float64, expected floa
 		t.Errorf("Summary mode didn't count %s jobs correctly. Actual: %f, expected: %f", state, actual, expected)
 	}
 }
-
-// fakeManager implements the Manager interface for testing.
-type fakeManager struct {
-	result string
-	err    error
-}
-
-// GetManagerProperty returns the controlled result for tests.
-func (f *fakeManager) GetManagerProperty(prop string) (string, error) {
-	return f.result, f.err
-}
-
-func Test_systemdCollector_getSystemdVirtualization(t *testing.T) {
-	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
-	c, err := NewSystemdCollector(logger)
-	if err != nil {
-		t.Fatal(err)
-	}
-	sysdCollector := c.(*systemdCollector)
-
-	tests := []struct {
-		name string
-		fake *fakeManager
-		want string
-	}{
-		{
-			name: "Error",
-			fake: &fakeManager{
-				err: errors.New("test error"),
-			},
-			want: "unknown",
-		},
-		{
-			name: "Empty",
-			fake: &fakeManager{
-				result: `""`,
-			},
-			want: "none",
-		},
-		{
-			name: "Valid",
-			fake: &fakeManager{
-				result: `"kvm"`,
-			},
-			want: "kvm",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got := sysdCollector.getSystemdVirtualization(tt.fake)
-			if got != tt.want {
-				t.Errorf("getSystemdVirtualization() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}