diff --git a/cmd/mungedocs/toc.go b/cmd/mungedocs/toc.go
index 86f9677f634..9011e117db9 100644
--- a/cmd/mungedocs/toc.go
+++ b/cmd/mungedocs/toc.go
@@ -35,7 +35,8 @@ func updateTOC(filePath string, markdown []byte) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	updatedMarkdown, err := updateMacroBlock(markdown, "<!-- BEGIN GENERATED TOC -->", "<!-- END GENERATED TOC -->", string(toc))
+	lines := splitLines(markdown)
+	updatedMarkdown, err := updateMacroBlock(lines, "<!-- BEGIN GENERATED TOC -->", "<!-- END GENERATED TOC -->", string(toc))
 	if err != nil {
 		return nil, err
 	}
diff --git a/cmd/mungedocs/util.go b/cmd/mungedocs/util.go
index 6a55f0aa9be..f26df9b714c 100644
--- a/cmd/mungedocs/util.go
+++ b/cmd/mungedocs/util.go
@@ -22,17 +22,23 @@ import (
 	"strings"
 )
 
-// Replaces the text between matching "beginMark" and "endMark" within "document" with "insertThis".
-//
-// Delimiters should occupy own line.
-// Returns copy of document with modifications.
-func updateMacroBlock(document []byte, beginMark, endMark, insertThis string) ([]byte, error) {
-	var buffer bytes.Buffer
+// Splits a document up into a slice of lines.
+func splitLines(document []byte) []string {
 	lines := strings.Split(string(document), "\n")
 	// Skip trailing empty string from Split-ing
 	if len(lines) > 0 && lines[len(lines)-1] == "" {
 		lines = lines[:len(lines)-1]
 	}
+	return lines
+}
+
+// Replaces the text between matching "beginMark" and "endMark" within the
+// document represented by "lines" with "insertThis".
+//
+// Delimiters should occupy own line.
+// Returns copy of document with modifications.
+func updateMacroBlock(lines []string, beginMark, endMark, insertThis string) ([]byte, error) {
+	var buffer bytes.Buffer
 	betweenBeginAndEnd := false
 	for _, line := range lines {
 		trimmedLine := strings.Trim(line, " \n")
diff --git a/cmd/mungedocs/util_test.go b/cmd/mungedocs/util_test.go
index 68454c1c779..49fbcee6381 100644
--- a/cmd/mungedocs/util_test.go
+++ b/cmd/mungedocs/util_test.go
@@ -34,7 +34,7 @@ func Test_updateMacroBlock(t *testing.T) {
 			"Lorem ipsum \n BEGIN\nfoo\n\nEND\nsit amet\n"},
 	}
 	for _, c := range cases {
-		actual, err := updateMacroBlock([]byte(c.in), "BEGIN", "END", "foo\n")
+		actual, err := updateMacroBlock(splitLines([]byte(c.in)), "BEGIN", "END", "foo\n")
 		assert.NoError(t, err)
 		if c.out != string(actual) {
 			t.Errorf("Expected '%v' but got '%v'", c.out, string(actual))
@@ -56,7 +56,7 @@ func Test_updateMacroBlock_errors(t *testing.T) {
 		{"BEGIN\nBEGIN\nEND\nEND"},
 	}
 	for _, c := range cases {
-		_, err := updateMacroBlock([]byte(c.in), "BEGIN", "END", "foo")
+		_, err := updateMacroBlock(splitLines([]byte(c.in)), "BEGIN", "END", "foo")
 		assert.Error(t, err)
 	}
 }