diff --git a/zsh_completions.go b/zsh_completions.go
index 12755482f0..b58a5d68f6 100644
--- a/zsh_completions.go
+++ b/zsh_completions.go
@@ -332,5 +332,7 @@ func zshCompFlagCouldBeSpecifiedMoreThenOnce(f *pflag.Flag) bool {
 }
 
 func zshCompQuoteFlagDescription(s string) string {
-	return strings.Replace(s, "'", `'\''`, -1)
+	return strings.NewReplacer("'", `'\''`,
+		"[", `\[`,
+		"]", `\]`).Replace(s)
 }
diff --git a/zsh_completions_test.go b/zsh_completions_test.go
index e53fa886e5..8079f6cf72 100644
--- a/zsh_completions_test.go
+++ b/zsh_completions_test.go
@@ -157,6 +157,17 @@ func TestGenZshCompletion(t *testing.T) {
 				`--private\[Don'\\''t show public info]`,
 			},
 		},
+		{
+			name: "flag description with brackets ([]) shouldn't break the completion file",
+			root: func() *Command {
+				r := genTestCommand("root", true)
+				r.Flags().Bool("level", false, "[ALERT]")
+				return r
+			}(),
+			expectedExpressions: []string{
+				`--level[\[ALERT\]]`,
+			},
+		},
 		{
 			name: "argument completion for file with and without patterns",
 			root: func() *Command {