diff --git a/src/progress_bar.rs b/src/progress_bar.rs
index af28595b..09a8a2cc 100644
--- a/src/progress_bar.rs
+++ b/src/progress_bar.rs
@@ -264,9 +264,9 @@ impl ProgressBar {
             .extend(msg.as_ref().lines().map(Into::into));
         draw_state.orphan_lines = draw_state.lines.len();
         if draw_lines {
-            draw_state
-                .lines
-                .extend(state.style.format_state(&state, width));
+            state
+                .style
+                .format_state(&state, &mut draw_state.lines, width);
         }
 
         drop(draw_state);
diff --git a/src/state.rs b/src/state.rs
index e1f33c22..04ff96bb 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -120,10 +120,11 @@ impl BarState {
         // finished progress bar, so it's kept as to not cause compatibility issues in weird cases.
         draw_state.force_draw = force_draw || self.state.is_finished();
 
-        draw_state.lines = match self.state.should_render() {
-            true => self.state.style.format_state(&self.state, width),
-            false => Vec::new(),
-        };
+        if self.state.should_render() {
+            self.state
+                .style
+                .format_state(&self.state, &mut draw_state.lines, width);
+        }
 
         drop(draw_state);
         drawable.draw()
diff --git a/src/style.rs b/src/style.rs
index a176243d..9caf99ca 100644
--- a/src/style.rs
+++ b/src/style.rs
@@ -227,10 +227,14 @@ impl ProgressStyle {
         }
     }
 
-    pub(crate) fn format_state(&self, state: &ProgressState, target_width: usize) -> Vec<String> {
+    pub(crate) fn format_state(
+        &self,
+        state: &ProgressState,
+        lines: &mut Vec<String>,
+        target_width: usize,
+    ) {
         let mut cur = String::new();
         let mut buf = String::new();
-        let mut rv = vec![];
         let mut wide = None;
         for part in &self.template.parts {
             match part {
@@ -359,7 +363,7 @@ impl ProgressStyle {
                     }
                 }
                 TemplatePart::Literal(s) => cur.push_str(s),
-                TemplatePart::NewLine => rv.push(match wide {
+                TemplatePart::NewLine => lines.push(match wide {
                     Some(inner) => {
                         inner.expand(mem::take(&mut cur), self, state, &mut buf, target_width)
                     }
@@ -369,14 +373,13 @@ impl ProgressStyle {
         }
 
         if !cur.is_empty() {
-            rv.push(match wide {
+            lines.push(match wide {
                 Some(inner) => {
                     inner.expand(mem::take(&mut cur), self, state, &mut buf, target_width)
                 }
                 None => mem::take(&mut cur),
             })
         }
-        rv
     }
 }
 
@@ -713,46 +716,55 @@ mod tests {
 
     #[test]
     fn test_expand_template() {
-        let mut style = ProgressStyle::default_bar();
-        style.format_map.0.insert("foo", |_| "FOO".into());
-        style.format_map.0.insert("bar", |_| "BAR".into());
         let draw_target = ProgressDrawTarget::stdout();
         let width = draw_target.width();
         let state = ProgressState::new(10);
+        let mut buf = Vec::new();
+
+        let mut style = ProgressStyle::default_bar();
+        style.format_map.0.insert("foo", |_| "FOO".into());
+        style.format_map.0.insert("bar", |_| "BAR".into());
 
         style.template = Template::from_str("{{ {foo} {bar} }}");
-        let rv = style.format_state(&state, width);
-        assert_eq!(&rv[0], "{ FOO BAR }");
+        style.format_state(&state, &mut buf, width);
+        assert_eq!(&buf[0], "{ FOO BAR }");
 
+        buf.clear();
         style.template = Template::from_str(r#"{ "foo": "{foo}", "bar": {bar} }"#);
-        let rv = style.format_state(&state, width);
-        assert_eq!(&rv[0], r#"{ "foo": "FOO", "bar": BAR }"#);
+        style.format_state(&state, &mut buf, width);
+        assert_eq!(&buf[0], r#"{ "foo": "FOO", "bar": BAR }"#);
     }
 
     #[test]
     fn test_expand_template_flags() {
         use console::set_colors_enabled;
         set_colors_enabled(true);
-        let mut style = ProgressStyle::default_bar();
-        style.format_map.0.insert("foo", |_| "XXX".into());
+
         let draw_target = ProgressDrawTarget::stdout();
         let width = draw_target.width();
         let state = ProgressState::new(10);
+        let mut buf = Vec::new();
+
+        let mut style = ProgressStyle::default_bar();
+        style.format_map.0.insert("foo", |_| "XXX".into());
 
         style.template = Template::from_str("{foo:5}");
-        let rv = style.format_state(&state, width);
-        assert_eq!(&rv[0], "XXX  ");
+        style.format_state(&state, &mut buf, width);
+        assert_eq!(&buf[0], "XXX  ");
 
+        buf.clear();
         style.template = Template::from_str("{foo:.red.on_blue}");
-        let rv = style.format_state(&state, width);
-        assert_eq!(&rv[0], "\u{1b}[31m\u{1b}[44mXXX\u{1b}[0m");
+        style.format_state(&state, &mut buf, width);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44mXXX\u{1b}[0m");
 
+        buf.clear();
         style.template = Template::from_str("{foo:^5.red.on_blue}");
-        let rv = style.format_state(&state, width);
-        assert_eq!(&rv[0], "\u{1b}[31m\u{1b}[44m XXX \u{1b}[0m");
+        style.format_state(&state, &mut buf, width);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44m XXX \u{1b}[0m");
 
+        buf.clear();
         style.template = Template::from_str("{foo:^5.red.on_blue/green.on_cyan}");
-        let rv = style.format_state(&state, width);
-        assert_eq!(&rv[0], "\u{1b}[31m\u{1b}[44m XXX \u{1b}[0m");
+        style.format_state(&state, &mut buf, width);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44m XXX \u{1b}[0m");
     }
 }