diff --git a/pkg/app2/appserver/proc_manager.go b/pkg/app2/appserver/proc_manager.go
index fa891d649..c21532bd8 100644
--- a/pkg/app2/appserver/proc_manager.go
+++ b/pkg/app2/appserver/proc_manager.go
@@ -14,6 +14,7 @@ import (
 
 var (
 	errAppAlreadyExists = errors.New("app already exists")
+	errNoSuchApp        = errors.New("no such app")
 )
 
 // ProcManager allows to manage skywire applications.
@@ -117,7 +118,7 @@ func (m *ProcManager) pop(name string) (*Proc, error) {
 
 	p, ok := m.procs[name]
 	if !ok {
-		return nil, errors.New("no such app")
+		return nil, errNoSuchApp
 	}
 
 	delete(m.procs, name)
diff --git a/pkg/app2/appserver/proc_manager_test.go b/pkg/app2/appserver/proc_manager_test.go
new file mode 100644
index 000000000..a71da50e3
--- /dev/null
+++ b/pkg/app2/appserver/proc_manager_test.go
@@ -0,0 +1,63 @@
+package appserver
+
+import (
+	"sort"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/skycoin/skycoin/src/util/logging"
+)
+
+func TestProcManager_Exists(t *testing.T) {
+	m := NewProcManager(logging.MustGetLogger("proc_manager"))
+
+	appName := "app"
+
+	ok := m.Exists(appName)
+	require.False(t, ok)
+
+	m.procs[appName] = nil
+
+	ok = m.Exists(appName)
+	require.True(t, ok)
+}
+
+func TestProcManager_Range(t *testing.T) {
+	m := NewProcManager(logging.MustGetLogger("proc_manager"))
+
+	wantAppNames := []string{"app1", "app2", "app3"}
+
+	for _, n := range wantAppNames {
+		m.procs[n] = nil
+	}
+
+	var gotAppNames []string
+	next := func(name string, app *Proc) bool {
+		gotAppNames = append(gotAppNames, name)
+		require.Nil(t, app)
+		return true
+	}
+
+	m.Range(next)
+
+	sort.Strings(gotAppNames)
+	require.Equal(t, gotAppNames, wantAppNames)
+}
+
+func TestProcManager_Pop(t *testing.T) {
+	m := NewProcManager(logging.MustGetLogger("proc_manager"))
+
+	appName := "app"
+
+	app, err := m.pop(appName)
+	require.Equal(t, err, errNoSuchApp)
+
+	m.procs[appName] = nil
+
+	app, err = m.pop(appName)
+	require.NoError(t, err)
+	require.Nil(t, app)
+	_, ok := m.procs[appName]
+	require.False(t, ok)
+}