diff --git a/apis/v1alpha1/convert_test.go b/apis/v1alpha1/convert_test.go
index f7952702ce..4f0af2602c 100644
--- a/apis/v1alpha1/convert_test.go
+++ b/apis/v1alpha1/convert_test.go
@@ -323,6 +323,65 @@ func Test_tov1beta1AndBack(t *testing.T) {
 	assert.Equal(t, colalpha1, colalpha1Converted)
 }
 
+func Test_tov1beta1AndBack_prometheus_selectors(t *testing.T) {
+	t.Run("nil-selectors", func(t *testing.T) {
+		colalpha1 := OpenTelemetryCollector{
+			Spec: OpenTelemetryCollectorSpec{
+				TargetAllocator: OpenTelemetryTargetAllocator{
+					PrometheusCR: OpenTelemetryTargetAllocatorPrometheusCR{
+						// nil or empty map means select everything
+						PodMonitorSelector:     nil,
+						ServiceMonitorSelector: nil,
+					},
+				},
+			},
+		}
+
+		colbeta1 := v1beta1.OpenTelemetryCollector{}
+		err := colalpha1.ConvertTo(&colbeta1)
+		require.NoError(t, err)
+
+		// nil LabelSelector means select nothing
+		// empty LabelSelector mean select everything
+		assert.NotNil(t, colbeta1.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector)
+		assert.NotNil(t, colbeta1.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector)
+		assert.Equal(t, 0, len(colalpha1.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector))
+		assert.Equal(t, 0, len(colalpha1.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector))
+
+		err = colalpha1.ConvertFrom(&colbeta1)
+		require.NoError(t, err)
+		assert.Nil(t, colalpha1.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector)
+		assert.Nil(t, colalpha1.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector)
+	})
+	t.Run("empty-selectors", func(t *testing.T) {
+		colalpha1 := OpenTelemetryCollector{
+			Spec: OpenTelemetryCollectorSpec{
+				TargetAllocator: OpenTelemetryTargetAllocator{
+					PrometheusCR: OpenTelemetryTargetAllocatorPrometheusCR{
+						// nil or empty map means select everything
+						PodMonitorSelector:     map[string]string{},
+						ServiceMonitorSelector: map[string]string{},
+					},
+				},
+			},
+		}
+
+		colbeta1 := v1beta1.OpenTelemetryCollector{}
+		err := colalpha1.ConvertTo(&colbeta1)
+		require.NoError(t, err)
+
+		// nil LabelSelector means select nothing
+		// empty LabelSelector mean select everything
+		assert.NotNil(t, colbeta1.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector)
+		assert.NotNil(t, colbeta1.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector)
+
+		err = colalpha1.ConvertFrom(&colbeta1)
+		require.NoError(t, err)
+		assert.Equal(t, map[string]string{}, colalpha1.Spec.TargetAllocator.PrometheusCR.PodMonitorSelector)
+		assert.Equal(t, map[string]string{}, colalpha1.Spec.TargetAllocator.PrometheusCR.ServiceMonitorSelector)
+	})
+}
+
 func createTA() OpenTelemetryTargetAllocator {
 	replicas := int32(2)
 	runAsNonRoot := true