diff --git a/filters/shedder/admission.go b/filters/shedder/admission.go
index 1ba1ba3d45..a5c8d815a1 100644
--- a/filters/shedder/admission.go
+++ b/filters/shedder/admission.go
@@ -95,44 +95,7 @@ type Options struct {
 	Tracer opentracing.Tracer
 }
 
-type AdmissionControlSpec struct {
-	tracer opentracing.Tracer
-}
-
-type admissionControl struct {
-	once   sync.Once
-	mu     sync.Mutex
-	quit   chan struct{}
-	closed bool
-
-	metrics      metrics.Metrics
-	metricSuffix string
-	tracer       opentracing.Tracer
-
-	mode                 mode
-	windowSize           int
-	minRps               int
-	d                    time.Duration
-	successThreshold     float64 // (0,1]
-	maxRejectProbability float64 // (0,1]
-	exponent             float64 // >0
-
-	averageRpsFactor float64
-	totals           []int64
-	success          []int64
-	counter          *atomic.Int64
-	successCounter   *atomic.Int64
-}
-
-func NewAdmissionControl(o Options) filters.Spec {
-	tracer := o.Tracer
-	if tracer == nil {
-		tracer = &opentracing.NoopTracer{}
-	}
-	return &AdmissionControlSpec{
-		tracer: tracer,
-	}
-}
+type admissionControlPre struct{}
 
 // Do removes duplcate filters, because we can only handle one in a
 // chain. The last one will override the others.
@@ -160,6 +123,11 @@ func (spec *admissionControlPre) Do(routes []*eskip.Route) []*eskip.Route {
 	return routes
 }
 
+type admissionControlPost struct {
+	mu      sync.Mutex // required for testing
+	filters map[string]*admissionControl
+}
+
 // Do implements routing.PostProcessor and makes it possible to close goroutines.
 func (spec *admissionControlPost) Do(routes []*routing.Route) []*routing.Route {
 	inUse := make(map[string]struct{})
@@ -191,10 +159,43 @@ func (spec *admissionControlPost) Do(routes []*routing.Route) []*routing.Route {
 	return routes
 }
 
-type admissionControlPre struct{}
-type admissionControlPost struct {
-	mu      sync.Mutex
-	filters map[string]*admissionControl
+type AdmissionControlSpec struct {
+	tracer opentracing.Tracer
+}
+
+type admissionControl struct {
+	once   sync.Once
+	mu     sync.Mutex
+	quit   chan struct{}
+	closed bool
+
+	metrics      metrics.Metrics
+	metricSuffix string
+	tracer       opentracing.Tracer
+
+	mode                 mode
+	windowSize           int
+	minRps               int
+	d                    time.Duration
+	successThreshold     float64 // (0,1]
+	maxRejectProbability float64 // (0,1]
+	exponent             float64 // >0
+
+	averageRpsFactor float64
+	totals           []int64
+	success          []int64
+	counter          *atomic.Int64
+	successCounter   *atomic.Int64
+}
+
+func NewAdmissionControl(o Options) filters.Spec {
+	tracer := o.Tracer
+	if tracer == nil {
+		tracer = &opentracing.NoopTracer{}
+	}
+	return &AdmissionControlSpec{
+		tracer: tracer,
+	}
 }
 
 func (*AdmissionControlSpec) PreProcessor() *admissionControlPre {