diff --git a/code.go b/code.go
index 5e4c3e2..c341a74 100644
--- a/code.go
+++ b/code.go
@@ -251,7 +251,6 @@ func commentAnnotations(src string) []Annotation {
 			annotations = append(annotations, Annotation{Kind: CommentAnnotation, Pos: int16(p), End: int16(e)})
 		}
 	}
-	return nil
 }
 
 type sliceWriter struct{ p *[]byte }
diff --git a/run.go b/run.go
index f1f97bb..8ef769c 100644
--- a/run.go
+++ b/run.go
@@ -119,7 +119,6 @@ func runApp(cmd *Command, args []string) int {
 			runtime.Goexit()
 		}
 	}
-	return 0
 }
 
 func readAppDirectories(directory string, paths *[]string) {
diff --git a/test.go b/test.go
index 6790c42..de5116d 100644
--- a/test.go
+++ b/test.go
@@ -73,7 +73,6 @@ func testApp(cmd *Command, args []string) int {
 			runTest()
 		}
 	}
-	return 0
 }
 
 func runTest() {
diff --git a/util.go b/util.go
index 1b8685d..0f314df 100644
--- a/util.go
+++ b/util.go
@@ -152,7 +152,6 @@ func getColorLevel(level string) string {
 	default:
 		return level
 	}
-	return level
 }
 
 // IsExist returns whether a file or directory exists.
@@ -252,7 +251,7 @@ func camelString(s string) string {
 type strFlags []string
 
 func (s *strFlags) String() string {
-	return fmt.Sprintf("%d", *s)
+	return fmt.Sprintf("%s", *s)
 }
 
 func (s *strFlags) Set(value string) error {