diff --git a/branchrestrictions.go b/branchrestrictions.go
index 529e90f..6928780 100644
--- a/branchrestrictions.go
+++ b/branchrestrictions.go
@@ -2,9 +2,7 @@ package bitbucket
 
 import (
 	"encoding/json"
-	"os"
 
-	"github.com/k0kubun/pp"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -23,7 +21,10 @@ func (b *BranchRestrictions) Gets(bo *BranchRestrictionsOptions) (interface{}, e
 }
 
 func (b *BranchRestrictions) Create(bo *BranchRestrictionsOptions) (*BranchRestrictions, error) {
-	data := b.buildBranchRestrictionsBody(bo)
+	data, err := b.buildBranchRestrictionsBody(bo)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := b.c.requestUrl("/repositories/%s/%s/branch-restrictions", bo.Owner, bo.RepoSlug)
 	response, err := b.c.execute("POST", urlStr, data)
 	if err != nil {
@@ -44,7 +45,10 @@ func (b *BranchRestrictions) Get(bo *BranchRestrictionsOptions) (*BranchRestrict
 }
 
 func (b *BranchRestrictions) Update(bo *BranchRestrictionsOptions) (interface{}, error) {
-	data := b.buildBranchRestrictionsBody(bo)
+	data, err := b.buildBranchRestrictionsBody(bo)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := b.c.requestUrl("/repositories/%s/%s/branch-restrictions/%s", bo.Owner, bo.RepoSlug, bo.ID)
 	response, err := b.c.execute("PUT", urlStr, data)
 	if err != nil {
@@ -115,8 +119,7 @@ type branchRestrictionsBodyUser struct {
 	} `json:"links"`
 }
 
-func (b *BranchRestrictions) buildBranchRestrictionsBody(bo *BranchRestrictionsOptions) string {
-
+func (b *BranchRestrictions) buildBranchRestrictionsBody(bo *BranchRestrictionsOptions) (string, error) {
 	var users []branchRestrictionsBodyUser
 	var groups []branchRestrictionsBodyGroup
 	for _, u := range bo.Users {
@@ -142,11 +145,10 @@ func (b *BranchRestrictions) buildBranchRestrictionsBody(bo *BranchRestrictionsO
 
 	data, err := json.Marshal(body)
 	if err != nil {
-		pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
 func decodeBranchRestriction(branchResponse interface{}) (*BranchRestrictions, error) {
diff --git a/deploykeys.go b/deploykeys.go
index 32d0be7..e105bf2 100644
--- a/deploykeys.go
+++ b/deploykeys.go
@@ -2,9 +2,7 @@ package bitbucket
 
 import (
 	"encoding/json"
-	"os"
 
-	"github.com/k0kubun/pp"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -35,22 +33,24 @@ func decodeDeployKey(response interface{}) (*DeployKey, error) {
 	return deployKey, nil
 }
 
-func buildDeployKeysBody(opt *DeployKeyOptions) string {
+func buildDeployKeysBody(opt *DeployKeyOptions) (string, error) {
 	body := map[string]interface{}{}
 	body["label"] = opt.Label
 	body["key"] = opt.Key
 
 	data, err := json.Marshal(body)
 	if err != nil {
-		_, _ = pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
 func (dk *DeployKeys) Create(opt *DeployKeyOptions) (*DeployKey, error) {
-	data := buildDeployKeysBody(opt)
+	data, err := buildDeployKeysBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := dk.c.requestUrl("/repositories/%s/%s/deploy-keys", opt.Owner, opt.RepoSlug)
 	response, err := dk.c.execute("POST", urlStr, data)
 	if err != nil {
diff --git a/issues.go b/issues.go
index 98dec73..454ac4c 100644
--- a/issues.go
+++ b/issues.go
@@ -4,10 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/url"
-	"os"
 	"strings"
-
-	"github.com/k0kubun/pp"
 )
 
 type Issues struct {
@@ -54,13 +51,19 @@ func (p *Issues) Delete(io *IssuesOptions) (interface{}, error) {
 }
 
 func (p *Issues) Update(io *IssuesOptions) (interface{}, error) {
-	data := p.buildIssueBody(io)
+	data, err := p.buildIssueBody(io)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := p.c.requestUrl("/repositories/%s/%s/issues/%s", io.Owner, io.RepoSlug, io.ID)
 	return p.c.execute("PUT", urlStr, data)
 }
 
 func (p *Issues) Create(io *IssuesOptions) (interface{}, error) {
-	data := p.buildIssueBody(io)
+	data, err := p.buildIssueBody(io)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := p.c.requestUrl("/repositories/%s/%s/issues", io.Owner, io.RepoSlug)
 	return p.c.execute("POST", urlStr, data)
 }
@@ -109,7 +112,7 @@ func (p *Issues) DeleteWatch(io *IssuesOptions) error {
 	return err
 }
 
-func (p *Issues) buildIssueBody(io *IssuesOptions) string {
+func (p *Issues) buildIssueBody(io *IssuesOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	// This feld is required
@@ -160,11 +163,10 @@ func (p *Issues) buildIssueBody(io *IssuesOptions) string {
 
 	data, err := json.Marshal(body)
 	if err != nil {
-		pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
 func (p *Issues) GetComments(ico *IssueCommentsOptions) (interface{}, error) {
diff --git a/project.go b/project.go
index 1bc8657..92d5478 100644
--- a/project.go
+++ b/project.go
@@ -2,9 +2,7 @@ package bitbucket
 
 import (
 	"encoding/json"
-	"os"
 
-	"github.com/k0kubun/pp"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -38,7 +36,10 @@ func (t *Workspace) GetProject(opt *ProjectOptions) (*Project, error) {
 }
 
 func (t *Workspace) CreateProject(opt *ProjectOptions) (*Project, error) {
-	data := t.buildProjectBody(opt)
+	data, err := t.buildProjectBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := t.c.requestUrl("/workspaces/%s/projects", opt.Owner)
 	response, err := t.c.execute("POST", urlStr, data)
 	if err != nil {
@@ -54,7 +55,10 @@ func (t *Workspace) DeleteProject(opt *ProjectOptions) (interface{}, error) {
 }
 
 func (t *Workspace) UpdateProject(opt *ProjectOptions) (*Project, error) {
-	data := t.buildProjectBody(opt)
+	data, err := t.buildProjectBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := t.c.requestUrl("/workspaces/%s/projects/%s", opt.Owner, opt.Key)
 	response, err := t.c.execute("PUT", urlStr, data)
 	if err != nil {
@@ -64,17 +68,16 @@ func (t *Workspace) UpdateProject(opt *ProjectOptions) (*Project, error) {
 	return decodeProject(response)
 }
 
-func (t *Workspace) buildJsonBody(body map[string]interface{}) string {
+func (t *Workspace) buildJsonBody(body map[string]interface{}) (string, error) {
 	data, err := json.Marshal(body)
 	if err != nil {
-		pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
-func (t *Workspace) buildProjectBody(opts *ProjectOptions) string {
+func (t *Workspace) buildProjectBody(opts *ProjectOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if opts.Description != "" {
diff --git a/pullrequests.go b/pullrequests.go
index 30231b1..bc15add 100644
--- a/pullrequests.go
+++ b/pullrequests.go
@@ -3,9 +3,6 @@ package bitbucket
 import (
 	"encoding/json"
 	"net/url"
-	"os"
-
-	"github.com/k0kubun/pp"
 )
 
 type PullRequests struct {
@@ -13,13 +10,19 @@ type PullRequests struct {
 }
 
 func (p *PullRequests) Create(po *PullRequestsOptions) (interface{}, error) {
-	data := p.buildPullRequestBody(po)
+	data, err := p.buildPullRequestBody(po)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := p.c.requestUrl("/repositories/%s/%s/pullrequests/", po.Owner, po.RepoSlug)
 	return p.c.execute("POST", urlStr, data)
 }
 
 func (p *PullRequests) Update(po *PullRequestsOptions) (interface{}, error) {
-	data := p.buildPullRequestBody(po)
+	data, err := p.buildPullRequestBody(po)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := p.c.GetApiBaseURL() + "/repositories/" + po.Owner + "/" + po.RepoSlug + "/pullrequests/" + po.ID
 	return p.c.execute("PUT", urlStr, data)
 }
@@ -96,13 +99,19 @@ func (p *PullRequests) Diff(po *PullRequestsOptions) (interface{}, error) {
 }
 
 func (p *PullRequests) Merge(po *PullRequestsOptions) (interface{}, error) {
-	data := p.buildPullRequestBody(po)
+	data, err := p.buildPullRequestBody(po)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := p.c.GetApiBaseURL() + "/repositories/" + po.Owner + "/" + po.RepoSlug + "/pullrequests/" + po.ID + "/merge"
 	return p.c.execute("POST", urlStr, data)
 }
 
 func (p *PullRequests) Decline(po *PullRequestsOptions) (interface{}, error) {
-	data := p.buildPullRequestBody(po)
+	data, err := p.buildPullRequestBody(po)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := p.c.GetApiBaseURL() + "/repositories/" + po.Owner + "/" + po.RepoSlug + "/pullrequests/" + po.ID + "/decline"
 	return p.c.execute("POST", urlStr, data)
 }
@@ -173,8 +182,7 @@ func (p *PullRequests) Statuses(po *PullRequestsOptions) (interface{}, error) {
 	return p.c.execute("GET", urlStr, "")
 }
 
-func (p *PullRequests) buildPullRequestBody(po *PullRequestsOptions) string {
-
+func (p *PullRequests) buildPullRequestBody(po *PullRequestsOptions) (string, error) {
 	body := map[string]interface{}{}
 	body["source"] = map[string]interface{}{}
 	body["destination"] = map[string]interface{}{}
@@ -225,11 +233,10 @@ func (p *PullRequests) buildPullRequestBody(po *PullRequestsOptions) string {
 
 	data, err := json.Marshal(body)
 	if err != nil {
-		pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
 func (p *PullRequests) buildPullRequestCommentBody(co *PullRequestCommentOptions) (string, error) {
diff --git a/repository.go b/repository.go
index 48c64be..805df96 100644
--- a/repository.go
+++ b/repository.go
@@ -6,12 +6,10 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/url"
-	"os"
 	"path"
 	"strconv"
 	"strings"
 
-	"github.com/k0kubun/pp"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -206,7 +204,10 @@ type DefaultReviewers struct {
 }
 
 func (r *Repository) Create(ro *RepositoryOptions) (*Repository, error) {
-	data := r.buildRepositoryBody(ro)
+	data, err := r.buildRepositoryBody(ro)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s", ro.Owner, ro.RepoSlug)
 	response, err := r.c.execute("POST", urlStr, data)
 	if err != nil {
@@ -217,7 +218,10 @@ func (r *Repository) Create(ro *RepositoryOptions) (*Repository, error) {
 }
 
 func (r *Repository) Fork(fo *RepositoryForkOptions) (*Repository, error) {
-	data := r.buildForkBody(fo)
+	data, err := r.buildForkBody(fo)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/forks", fo.FromOwner, fo.FromSlug)
 	response, err := r.c.execute("POST", urlStr, data)
 	if err != nil {
@@ -395,7 +399,10 @@ func (r *Repository) DeleteBranch(rbo *RepositoryBranchDeleteOptions) error {
 
 func (r *Repository) CreateBranch(rbo *RepositoryBranchCreationOptions) (*RepositoryBranch, error) {
 	urlStr := r.c.requestUrl("/repositories/%s/%s/refs/branches", rbo.Owner, rbo.RepoSlug)
-	data := r.buildBranchBody(rbo)
+	data, err := r.buildBranchBody(rbo)
+	if err != nil {
+		return nil, err
+	}
 
 	response, err := r.c.executeRaw("POST", urlStr, data)
 	if err != nil {
@@ -449,7 +456,10 @@ func (r *Repository) ListTags(rbo *RepositoryTagOptions) (*RepositoryTags, error
 
 func (r *Repository) CreateTag(rbo *RepositoryTagCreationOptions) (*RepositoryTag, error) {
 	urlStr := r.c.requestUrl("/repositories/%s/%s/refs/tags", rbo.Owner, rbo.RepoSlug)
-	data := r.buildTagBody(rbo)
+	data, err := r.buildTagBody(rbo)
+	if err != nil {
+		return nil, err
+	}
 
 	response, err := r.c.executeRaw("POST", urlStr, data)
 	if err != nil {
@@ -466,7 +476,10 @@ func (r *Repository) CreateTag(rbo *RepositoryTagCreationOptions) (*RepositoryTa
 }
 
 func (r *Repository) Update(ro *RepositoryOptions) (*Repository, error) {
-	data := r.buildRepositoryBody(ro)
+	data, err := r.buildRepositoryBody(ro)
+	if err != nil {
+		return nil, err
+	}
 	key := ro.RepoSlug
 	if ro.Uuid != "" {
 		key = ro.Uuid
@@ -532,7 +545,10 @@ func (r *Repository) DeleteDefaultReviewer(rdro *RepositoryDefaultReviewerOption
 }
 
 func (r *Repository) UpdatePipelineConfig(rpo *RepositoryPipelineOptions) (*Pipeline, error) {
-	data := r.buildPipelineBody(rpo)
+	data, err := r.buildPipelineBody(rpo)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/pipelines_config", rpo.Owner, rpo.RepoSlug)
 	response, err := r.c.execute("PUT", urlStr, data)
 	if err != nil {
@@ -579,7 +595,10 @@ func (r *Repository) ListPipelineVariables(opt *RepositoryPipelineVariablesOptio
 }
 
 func (r *Repository) AddPipelineVariable(rpvo *RepositoryPipelineVariableOptions) (*PipelineVariable, error) {
-	data := r.buildPipelineVariableBody(rpvo)
+	data, err := r.buildPipelineVariableBody(rpvo)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/pipelines_config/variables/", rpvo.Owner, rpvo.RepoSlug)
 
 	response, err := r.c.execute("POST", urlStr, data)
@@ -605,7 +624,10 @@ func (r *Repository) GetPipelineVariable(opt *RepositoryPipelineVariableOptions)
 }
 
 func (r *Repository) UpdatePipelineVariable(opt *RepositoryPipelineVariableOptions) (*PipelineVariable, error) {
-	data := r.buildPipelineVariableBody(opt)
+	data, err := r.buildPipelineVariableBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/pipelines_config/variables/%s", opt.Owner, opt.RepoSlug, opt.Uuid)
 	response, err := r.c.execute("PUT", urlStr, data)
 	if err != nil {
@@ -615,7 +637,10 @@ func (r *Repository) UpdatePipelineVariable(opt *RepositoryPipelineVariableOptio
 }
 
 func (r *Repository) AddPipelineKeyPair(rpkpo *RepositoryPipelineKeyPairOptions) (*PipelineKeyPair, error) {
-	data := r.buildPipelineKeyPairBody(rpkpo)
+	data, err := r.buildPipelineKeyPairBody(rpkpo)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/pipelines_config/ssh/key_pair", rpkpo.Owner, rpkpo.RepoSlug)
 
 	response, err := r.c.execute("PUT", urlStr, data)
@@ -627,7 +652,10 @@ func (r *Repository) AddPipelineKeyPair(rpkpo *RepositoryPipelineKeyPairOptions)
 }
 
 func (r *Repository) UpdatePipelineBuildNumber(rpbno *RepositoryPipelineBuildNumberOptions) (*PipelineBuildNumber, error) {
-	data := r.buildPipelineBuildNumberBody(rpbno)
+	data, err := r.buildPipelineBuildNumberBody(rpbno)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/pipelines_config/build_number", rpbno.Owner, rpbno.RepoSlug)
 
 	response, err := r.c.execute("PUT", urlStr, data)
@@ -664,7 +692,10 @@ func (r *Repository) ListEnvironments(opt *RepositoryEnvironmentsOptions) (*Envi
 }
 
 func (r *Repository) AddEnvironment(opt *RepositoryEnvironmentOptions) (*Environment, error) {
-	body := r.buildEnvironmentBody(opt)
+	body, err := r.buildEnvironmentBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/environments/", opt.Owner, opt.RepoSlug)
 	res, err := r.c.execute("POST", urlStr, body)
 	if err != nil {
@@ -725,7 +756,10 @@ func (r *Repository) ListDeploymentVariables(opt *RepositoryDeploymentVariablesO
 }
 
 func (r *Repository) AddDeploymentVariable(opt *RepositoryDeploymentVariableOptions) (*DeploymentVariable, error) {
-	body := r.buildDeploymentVariableBody(opt)
+	body, err := r.buildDeploymentVariableBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/deployments_config/environments/%s/variables", opt.Owner, opt.RepoSlug, opt.Environment.Uuid)
 
 	response, err := r.c.execute("POST", urlStr, body)
@@ -742,7 +776,10 @@ func (r *Repository) DeleteDeploymentVariable(opt *RepositoryDeploymentVariableD
 }
 
 func (r *Repository) UpdateDeploymentVariable(opt *RepositoryDeploymentVariableOptions) (*DeploymentVariable, error) {
-	body := r.buildDeploymentVariableBody(opt)
+	body, err := r.buildDeploymentVariableBody(opt)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/deployments_config/environments/%s/variables/%s", opt.Owner, opt.RepoSlug, opt.Environment.Uuid, opt.Uuid)
 
 	response, err := r.c.execute("PUT", urlStr, body)
@@ -753,8 +790,7 @@ func (r *Repository) UpdateDeploymentVariable(opt *RepositoryDeploymentVariableO
 	return decodeDeploymentVariable(response)
 }
 
-func (r *Repository) buildRepositoryBody(ro *RepositoryOptions) string {
-
+func (r *Repository) buildRepositoryBody(ro *RepositoryOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if ro.Uuid != "" {
@@ -807,8 +843,7 @@ func (r *Repository) buildRepositoryBody(ro *RepositoryOptions) string {
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildForkBody(fo *RepositoryForkOptions) string {
-
+func (r *Repository) buildForkBody(fo *RepositoryForkOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if fo.Owner != "" {
@@ -846,8 +881,7 @@ func (r *Repository) buildForkBody(fo *RepositoryForkOptions) string {
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildPipelineBody(rpo *RepositoryPipelineOptions) string {
-
+func (r *Repository) buildPipelineBody(rpo *RepositoryPipelineOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	body["enabled"] = rpo.Enabled
@@ -855,8 +889,7 @@ func (r *Repository) buildPipelineBody(rpo *RepositoryPipelineOptions) string {
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildPipelineVariableBody(rpvo *RepositoryPipelineVariableOptions) string {
-
+func (r *Repository) buildPipelineVariableBody(rpvo *RepositoryPipelineVariableOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if rpvo.Uuid != "" {
@@ -869,8 +902,7 @@ func (r *Repository) buildPipelineVariableBody(rpvo *RepositoryPipelineVariableO
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildPipelineKeyPairBody(rpkpo *RepositoryPipelineKeyPairOptions) string {
-
+func (r *Repository) buildPipelineKeyPairBody(rpkpo *RepositoryPipelineKeyPairOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if rpkpo.PrivateKey != "" {
@@ -883,8 +915,7 @@ func (r *Repository) buildPipelineKeyPairBody(rpkpo *RepositoryPipelineKeyPairOp
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildPipelineBuildNumberBody(rpbno *RepositoryPipelineBuildNumberOptions) string {
-
+func (r *Repository) buildPipelineBuildNumberBody(rpbno *RepositoryPipelineBuildNumberOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	body["next"] = rpbno.Next
@@ -892,7 +923,7 @@ func (r *Repository) buildPipelineBuildNumberBody(rpbno *RepositoryPipelineBuild
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildBranchBody(rbo *RepositoryBranchCreationOptions) string {
+func (r *Repository) buildBranchBody(rbo *RepositoryBranchCreationOptions) (string, error) {
 	body := map[string]interface{}{
 		"name": rbo.Name,
 		"target": map[string]string{
@@ -903,7 +934,7 @@ func (r *Repository) buildBranchBody(rbo *RepositoryBranchCreationOptions) strin
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildTagBody(rbo *RepositoryTagCreationOptions) string {
+func (r *Repository) buildTagBody(rbo *RepositoryTagCreationOptions) (string, error) {
 	body := map[string]interface{}{
 		"name": rbo.Name,
 		"target": map[string]string{
@@ -914,7 +945,7 @@ func (r *Repository) buildTagBody(rbo *RepositoryTagCreationOptions) string {
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildEnvironmentBody(opt *RepositoryEnvironmentOptions) string {
+func (r *Repository) buildEnvironmentBody(opt *RepositoryEnvironmentOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	body["environment_type"] = map[string]interface{}{
@@ -931,7 +962,7 @@ func (r *Repository) buildEnvironmentBody(opt *RepositoryEnvironmentOptions) str
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildDeploymentVariableBody(opt *RepositoryDeploymentVariableOptions) string {
+func (r *Repository) buildDeploymentVariableBody(opt *RepositoryDeploymentVariableOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if opt.Uuid != "" {
@@ -944,15 +975,13 @@ func (r *Repository) buildDeploymentVariableBody(opt *RepositoryDeploymentVariab
 	return r.buildJsonBody(body)
 }
 
-func (r *Repository) buildJsonBody(body map[string]interface{}) string {
-
+func (r *Repository) buildJsonBody(body map[string]interface{}) (string, error) {
 	data, err := json.Marshal(body)
 	if err != nil {
-		pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
 func decodeRepository(repoResponse interface{}) (*Repository, error) {
diff --git a/webhooks.go b/webhooks.go
index 7f7b1bc..4d592db 100644
--- a/webhooks.go
+++ b/webhooks.go
@@ -2,9 +2,7 @@ package bitbucket
 
 import (
 	"encoding/json"
-	"os"
 
-	"github.com/k0kubun/pp"
 	"github.com/mitchellh/mapstructure"
 )
 
@@ -38,8 +36,7 @@ func decodeWebhook(response interface{}) (*Webhook, error) {
 	return webhook, nil
 }
 
-func (r *Webhooks) buildWebhooksBody(ro *WebhooksOptions) string {
-
+func (r *Webhooks) buildWebhooksBody(ro *WebhooksOptions) (string, error) {
 	body := map[string]interface{}{}
 
 	if ro.Description != "" {
@@ -56,11 +53,10 @@ func (r *Webhooks) buildWebhooksBody(ro *WebhooksOptions) string {
 
 	data, err := json.Marshal(body)
 	if err != nil {
-		pp.Println(err)
-		os.Exit(9)
+		return "", err
 	}
 
-	return string(data)
+	return string(data), nil
 }
 
 func (r *Webhooks) Gets(ro *WebhooksOptions) (interface{}, error) {
@@ -69,7 +65,10 @@ func (r *Webhooks) Gets(ro *WebhooksOptions) (interface{}, error) {
 }
 
 func (r *Webhooks) Create(ro *WebhooksOptions) (*Webhook, error) {
-	data := r.buildWebhooksBody(ro)
+	data, err := r.buildWebhooksBody(ro)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/hooks", ro.Owner, ro.RepoSlug)
 	response, err := r.c.execute("POST", urlStr, data)
 	if err != nil {
@@ -90,7 +89,10 @@ func (r *Webhooks) Get(ro *WebhooksOptions) (*Webhook, error) {
 }
 
 func (r *Webhooks) Update(ro *WebhooksOptions) (*Webhook, error) {
-	data := r.buildWebhooksBody(ro)
+	data, err := r.buildWebhooksBody(ro)
+	if err != nil {
+		return nil, err
+	}
 	urlStr := r.c.requestUrl("/repositories/%s/%s/hooks/%s", ro.Owner, ro.RepoSlug, ro.Uuid)
 	response, err := r.c.execute("PUT", urlStr, data)
 	if err != nil {