diff --git a/CHANGELOG.md b/CHANGELOG.md
index db46649..685cba1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Writing a new mothball with the same name is now detected and the new mothball loaded (#172)
 - Regression test for issue where URL path leading directories were ignored (#144)
 
+### Changed
+- Many error messages were changed to start with a lower-case letter, 
+  in order to satisfy a new linter check.
+
 ## [v4.2.2] - 2021-09-30
 ### Added
 - `debug.notes` front matter field
diff --git a/cmd/mothd/mothballs_test.go b/cmd/mothd/mothballs_test.go
index 81e82e2..61bcd82 100644
--- a/cmd/mothd/mothballs_test.go
+++ b/cmd/mothd/mothballs_test.go
@@ -9,9 +9,11 @@ import (
 	"github.com/spf13/afero"
 )
 
-var testFiles = []struct {
+type testFileContents struct {
 	Name, Body string
-}{
+}
+
+var testFiles = []testFileContents{
 	{"puzzles.txt", "1\n3\n2\n"},
 	{"answers.txt", "1 answer123\n1 answer456\n2 wat\n"},
 	{"1/puzzle.json", `{"name": "moo"}`},
@@ -21,7 +23,7 @@ var testFiles = []struct {
 	{"3/moo.txt", `moo`},
 }
 
-func (m *Mothballs) createMothballWithMoo1(cat string, moo1 string) {
+func (m *Mothballs) createMothballWithFiles(cat string, contents []testFileContents) {
 	f, _ := m.Create(fmt.Sprintf("%s.mb", cat))
 	defer f.Close()
 
@@ -32,13 +34,19 @@ func (m *Mothballs) createMothballWithMoo1(cat string, moo1 string) {
 		of, _ := w.Create(file.Name)
 		of.Write([]byte(file.Body))
 	}
-
-	of, _ := w.Create("1/moo.txt")
-	of.Write([]byte(moo1))
+	for _, file := range contents {
+		of, _ := w.Create(file.Name)
+		of.Write([]byte(file.Body))
+	}
 }
 
 func (m *Mothballs) createMothball(cat string) {
-	m.createMothballWithMoo1(cat, "moo")
+	m.createMothballWithFiles(
+		cat,
+		[]testFileContents{
+			{"1/moo.txt", "moo"},
+		},
+	)
 }
 
 func NewTestMothballs() *Mothballs {
@@ -105,7 +113,12 @@ func TestMothballs(t *testing.T) {
 
 	goofyText := "bozonics"
 	//time.Sleep(1 * time.Second) // I don't love this, but we need the mtime to increase, and it's only accurate to 1s
-	m.createMothballWithMoo1("pategory", goofyText)
+	m.createMothballWithFiles(
+		"pategory",
+		[]testFileContents{
+			{"1/moo.txt", goofyText},
+		},
+	)
 	m.refresh()
 	if f, _, err := m.Open("pategory", 1, "moo.txt"); err != nil {
 		t.Error("pategory/1/moo.txt", err)