diff --git a/pkg/cover/client.go b/pkg/cover/client.go
index 6e0c82f..827c7c8 100644
--- a/pkg/cover/client.go
+++ b/pkg/cover/client.go
@@ -139,7 +139,10 @@ func (c *client) Remove(param ProfileParam) ([]byte, error) {
 
 	// the json.Marshal function can return two types of errors: UnsupportedTypeError or UnsupportedValueError
 	// so no need to check here
-	body, _ := json.Marshal(param)
+	body, err := json.Marshal(param)
+	if err != nil {
+		return nil, err
+	}
 	_, resp, err := c.do("POST", u, "application/json", bytes.NewReader(body))
 	if err != nil && isNetworkError(err) {
 		_, resp, err = c.do("POST", u, "application/json", bytes.NewReader(body))
diff --git a/pkg/cover/store.go b/pkg/cover/store.go
index 7429ee7..40861ca 100644
--- a/pkg/cover/store.go
+++ b/pkg/cover/store.go
@@ -172,7 +172,10 @@ func (l *fileStore) Set(services map[string][]string) error {
 	defer l.mu.Unlock()
 
 	// no error will return from memorystore.set
-	_ = l.memoryStore.Set(services)
+	err := l.memoryStore.Set(services)
+	if err != nil {
+		return err
+	}
 
 	f, err := os.OpenFile(l.persistentFile, os.O_TRUNC|os.O_WRONLY|os.O_CREATE, 0600)
 	if err != nil {
@@ -191,8 +194,7 @@ func (l *fileStore) Set(services map[string][]string) error {
 		return err
 	}
 
-	_ = f.Sync()
-	return nil
+	return f.Sync()
 }
 
 func (l *fileStore) appendToFile(s ServiceUnderTest) error {