diff --git a/calls.go b/calls.go
index 50dbe89..3f87612 100644
--- a/calls.go
+++ b/calls.go
@@ -278,22 +278,6 @@ type CallStreamGetSpecific struct {
 	StreamID            string `json:"stream_id" url:"stream_id"`
 }
 
-type VoiceInteractionResponse struct {
-	StartTime              string  `json:"start_time,omitempty" url:"start_time,omitempty"`
-	EndTime                string  `json:"end_time,omitempty" url:"end_time,omitempty"`
-	FirstPartyResourceUrl  string  `json:"first_party_resource_url,omitempty" url:"first_party_resource_url,omitempty"`
-	SecondPartyResourceUrl string  `json:"second_party_resource_url,omitempty" url:"second_party_resource_url,omitempty"`
-	FirstPartyStatus       string  `json:"first_party_status,omitempty" url:"first_party_status,omitempty"`
-	SecondPartyStatus      string  `json:"second_party_status,omitempty" url:"second_party_status,omitempty"`
-	Type                   string  `json:"type,omitempty" url:"type,omitempty"`
-	TotalCallAmount        float64 `json:"total_call_amount,omitempty" url:"total_call_amount,omitempty"`
-	CallBilledDuration     int     `json:"call_billed_duration,omitempty" url:"call_billed_duration,omitempty"`
-	RecordingResourceUrl   string  `json:"recording_resource_url,omitempty" url:"recording_resource_url,omitempty"`
-	AuthID                 string  `json:"auth_id,omitempty" url:"auth_id,omitempty"`
-	TotalCallCount         int     `json:"total_call_count" url:"total_call_count"`
-	Duration               float64 `json:"duration" url:"duration"`
-}
-
 func (service *CallService) List(params CallListParams) (response *CallListResponse, err error) {
 	req, err := service.client.NewRequest("GET", params, "Call")
 	if err != nil {
diff --git a/calls_test.go b/calls_test.go
index d9b5522..d943691 100644
--- a/calls_test.go
+++ b/calls_test.go
@@ -366,101 +366,3 @@ func TestCallService_GetAllStreams(t *testing.T) {
 
 	assertRequest(t, "GET", "Call/%s/Stream", CallID)
 }
-
-func TestCallService_CreateMaskingSession(t *testing.T) {
-	expectResponse("createMaskingSessionResponse.json", 200)
-
-	if _, err := client.MaskingSession.CreateMaskingSession(CreateMaskingSessionParams{}); err != nil {
-		panic(err)
-	}
-
-	cl := client.httpClient
-	client.httpClient = nil
-	_, err := client.MaskingSession.CreateMaskingSession(CreateMaskingSessionParams{})
-	if err == nil {
-		client.httpClient = cl
-		panic(errors.New("error expected"))
-	}
-	client.httpClient = cl
-
-	assertRequest(t, "POST", "Masking/Session")
-}
-
-func TestCallService_DeleteMaskingSession(t *testing.T) {
-	expectResponse("deleteMaskingSessionResponse.json", 204)
-	SessionUuid := "15e4256c-be01-475c-9a69-95cf65bbed71"
-
-	if _, err := client.MaskingSession.DeleteMaskingSession(SessionUuid); err != nil {
-		panic(err)
-	}
-
-	cl := client.httpClient
-	client.httpClient = nil
-	_, err := client.MaskingSession.DeleteMaskingSession(SessionUuid)
-	if err == nil {
-		client.httpClient = cl
-		panic(errors.New("error expected"))
-	}
-	client.httpClient = cl
-
-	assertRequest(t, "DELETE", "Masking/Session/%s", SessionUuid)
-}
-
-func TestCallService_GetMaskingSession(t *testing.T) {
-	expectResponse("getMaskingSessionResponse.json", 200)
-	SessionUuid := "15e4256c-be01-475c-9a69-95cf65bbed71"
-
-	if _, err := client.MaskingSession.GetMaskingSession(SessionUuid); err != nil {
-		panic(err)
-	}
-
-	cl := client.httpClient
-	client.httpClient = nil
-	_, err := client.MaskingSession.GetMaskingSession(SessionUuid)
-	if err == nil {
-		client.httpClient = cl
-		panic(errors.New("error expected"))
-	}
-	client.httpClient = cl
-
-	assertRequest(t, "GET", "Masking/Session/%s", SessionUuid)
-}
-
-func TestCallService_updateMaskingSession(t *testing.T) {
-	expectResponse("updateMaskingSessionResponse.json", 204)
-	SessionUuid := "15e4256c-be01-475c-9a69-95cf65bbed71"
-
-	if _, err := client.MaskingSession.UpdateMaskingSession(UpdateMaskingSessionParams{}, SessionUuid); err != nil {
-		panic(err)
-	}
-
-	cl := client.httpClient
-	client.httpClient = nil
-	_, err := client.MaskingSession.UpdateMaskingSession(UpdateMaskingSessionParams{}, SessionUuid)
-	if err == nil {
-		client.httpClient = cl
-		panic(errors.New("error expected"))
-	}
-	client.httpClient = cl
-
-	assertRequest(t, "POST", "Masking/Session/%s", SessionUuid)
-}
-
-func TestCallService_ListMaskingSession(t *testing.T) {
-	expectResponse("listMaskingSessionResponse.json", 204)
-
-	if _, err := client.MaskingSession.ListMaskingSession(ListSessionFilterParams{}); err != nil {
-		panic(err)
-	}
-
-	cl := client.httpClient
-	client.httpClient = nil
-	_, err := client.MaskingSession.ListMaskingSession(ListSessionFilterParams{})
-	if err == nil {
-		client.httpClient = cl
-		panic(errors.New("error expected"))
-	}
-	client.httpClient = cl
-
-	assertRequest(t, "GET", "Masking/Session")
-}
diff --git a/maskingsession.go b/maskingsession.go
index 494a646..4503ae3 100644
--- a/maskingsession.go
+++ b/maskingsession.go
@@ -89,6 +89,22 @@ type ListSessionFilterParams struct {
 	Offset                    int64  `json:"offset,omitempty" url:"offset,omitempty"`
 }
 
+type VoiceInteractionResponse struct {
+	StartTime              string  `json:"start_time,omitempty" url:"start_time,omitempty"`
+	EndTime                string  `json:"end_time,omitempty" url:"end_time,omitempty"`
+	FirstPartyResourceUrl  string  `json:"first_party_resource_url,omitempty" url:"first_party_resource_url,omitempty"`
+	SecondPartyResourceUrl string  `json:"second_party_resource_url,omitempty" url:"second_party_resource_url,omitempty"`
+	FirstPartyStatus       string  `json:"first_party_status,omitempty" url:"first_party_status,omitempty"`
+	SecondPartyStatus      string  `json:"second_party_status,omitempty" url:"second_party_status,omitempty"`
+	Type                   string  `json:"type,omitempty" url:"type,omitempty"`
+	TotalCallAmount        float64 `json:"total_call_amount,omitempty" url:"total_call_amount,omitempty"`
+	CallBilledDuration     int     `json:"call_billed_duration,omitempty" url:"call_billed_duration,omitempty"`
+	RecordingResourceUrl   string  `json:"recording_resource_url,omitempty" url:"recording_resource_url,omitempty"`
+	AuthID                 string  `json:"auth_id,omitempty" url:"auth_id,omitempty"`
+	TotalCallCount         int     `json:"total_call_count" url:"total_call_count"`
+	Duration               float64 `json:"duration" url:"duration"`
+}
+
 type CreateMaskingSessionResponse struct {
 	ApiID         string         `json:"api_id,omitempty" url:"api_id,omitempty"`
 	SessionUUID   string         `json:"session_uuid,omitempty" url:"session_uuid,omitempty"`
diff --git a/maskingsession_test.go b/maskingsession_test.go
new file mode 100644
index 0000000..d6437b2
--- /dev/null
+++ b/maskingsession_test.go
@@ -0,0 +1,104 @@
+package plivo
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestCallService_CreateMaskingSession(t *testing.T) {
+	expectResponse("createMaskingSessionResponse.json", 200)
+
+	if _, err := client.MaskingSession.CreateMaskingSession(CreateMaskingSessionParams{}); err != nil {
+		panic(err)
+	}
+
+	cl := client.httpClient
+	client.httpClient = nil
+	_, err := client.MaskingSession.CreateMaskingSession(CreateMaskingSessionParams{})
+	if err == nil {
+		client.httpClient = cl
+		panic(errors.New("error expected"))
+	}
+	client.httpClient = cl
+
+	assertRequest(t, "POST", "Masking/Session")
+}
+
+func TestCallService_DeleteMaskingSession(t *testing.T) {
+	expectResponse("deleteMaskingSessionResponse.json", 204)
+	SessionUuid := "15e4256c-be01-475c-9a69-95cf65bbed71"
+
+	if _, err := client.MaskingSession.DeleteMaskingSession(SessionUuid); err != nil {
+		panic(err)
+	}
+
+	cl := client.httpClient
+	client.httpClient = nil
+	_, err := client.MaskingSession.DeleteMaskingSession(SessionUuid)
+	if err == nil {
+		client.httpClient = cl
+		panic(errors.New("error expected"))
+	}
+	client.httpClient = cl
+
+	assertRequest(t, "DELETE", "Masking/Session/%s", SessionUuid)
+}
+
+func TestCallService_GetMaskingSession(t *testing.T) {
+	expectResponse("getMaskingSessionResponse.json", 200)
+	SessionUuid := "15e4256c-be01-475c-9a69-95cf65bbed71"
+
+	if _, err := client.MaskingSession.GetMaskingSession(SessionUuid); err != nil {
+		panic(err)
+	}
+
+	cl := client.httpClient
+	client.httpClient = nil
+	_, err := client.MaskingSession.GetMaskingSession(SessionUuid)
+	if err == nil {
+		client.httpClient = cl
+		panic(errors.New("error expected"))
+	}
+	client.httpClient = cl
+
+	assertRequest(t, "GET", "Masking/Session/%s", SessionUuid)
+}
+
+func TestCallService_updateMaskingSession(t *testing.T) {
+	expectResponse("updateMaskingSessionResponse.json", 204)
+	SessionUuid := "15e4256c-be01-475c-9a69-95cf65bbed71"
+
+	if _, err := client.MaskingSession.UpdateMaskingSession(UpdateMaskingSessionParams{}, SessionUuid); err != nil {
+		panic(err)
+	}
+
+	cl := client.httpClient
+	client.httpClient = nil
+	_, err := client.MaskingSession.UpdateMaskingSession(UpdateMaskingSessionParams{}, SessionUuid)
+	if err == nil {
+		client.httpClient = cl
+		panic(errors.New("error expected"))
+	}
+	client.httpClient = cl
+
+	assertRequest(t, "POST", "Masking/Session/%s", SessionUuid)
+}
+
+func TestCallService_ListMaskingSession(t *testing.T) {
+	expectResponse("listMaskingSessionResponse.json", 204)
+
+	if _, err := client.MaskingSession.ListMaskingSession(ListSessionFilterParams{}); err != nil {
+		panic(err)
+	}
+
+	cl := client.httpClient
+	client.httpClient = nil
+	_, err := client.MaskingSession.ListMaskingSession(ListSessionFilterParams{})
+	if err == nil {
+		client.httpClient = cl
+		panic(errors.New("error expected"))
+	}
+	client.httpClient = cl
+
+	assertRequest(t, "GET", "Masking/Session")
+}