diff --git a/tools/tui/loop/api.go b/tools/tui/loop/api.go
index 946ef6793..86dfb51f1 100644
--- a/tools/tui/loop/api.go
+++ b/tools/tui/loop/api.go
@@ -625,27 +625,27 @@ func (self *Loop) DrawSizedText(text string, spec SizedText) {
 	b.WriteString("\x1b]66;")
 	sep := ""
 	if spec.Scale > 1 {
-		b.WriteString(fmt.Sprintf("%ss=%d", sep, min(spec.Scale, 7)))
+		fmt.Fprintf(&b, "%ss=%d", sep, min(spec.Scale, 7))
 		sep = ":"
 	}
 	if spec.Width > 0 {
-		b.WriteString(fmt.Sprintf("%sw=%d", sep, min(spec.Width, 7)))
+		fmt.Fprintf(&b, "%sw=%d", sep, min(spec.Width, 7))
 		sep = ":"
 	}
 	if spec.Subscale_numerator > 0 {
-		b.WriteString(fmt.Sprintf("%sn=%d", sep, min(spec.Subscale_numerator, 15)))
+		fmt.Fprintf(&b, "%sn=%d", sep, min(spec.Subscale_numerator, 15))
 		sep = ":"
 	}
 	if spec.Subscale_denominator > spec.Subscale_numerator {
-		b.WriteString(fmt.Sprintf("%sd=%d", sep, min(spec.Subscale_denominator, 15)))
+		fmt.Fprintf(&b, "%sd=%d", sep, min(spec.Subscale_denominator, 15))
 		sep = ":"
 	}
 	if spec.Horizontal_alignment > ALIGN_START {
-		b.WriteString(fmt.Sprintf("%sh=%d", sep, spec.Horizontal_alignment))
+		fmt.Fprintf(&b, "%sh=%d", sep, spec.Horizontal_alignment)
 		sep = ":"
 	}
 	if spec.Vertical_alignment > ALIGN_START {
-		b.WriteString(fmt.Sprintf("%sv=%d", sep, spec.Vertical_alignment))
+		fmt.Fprintf(&b, "%sv=%d", sep, spec.Vertical_alignment)
 		sep = ":"
 	}
 	b.WriteString(";")
diff --git a/tools/tui/loop/key-encoding.go b/tools/tui/loop/key-encoding.go
index 5cd2c60f0..46e9c6247 100644
--- a/tools/tui/loop/key-encoding.go
+++ b/tools/tui/loop/key-encoding.go
@@ -405,9 +405,9 @@ func (self *KeyEvent) AsCSI() string {
 	if self.Mods != 0 || action > 1 || self.Text != "" {
 		m := uint(self.Mods)
 		if action > 1 || m != 0 {
-			ans.WriteString(fmt.Sprintf(";%d", m+1))
+			fmt.Fprintf(ans, ";%d", m+1)
 			if action > 1 {
-				ans.WriteString(fmt.Sprintf(":%d", action))
+				fmt.Fprintf(ans, ":%d", action)
 			}
 		} else if self.Text != "" {
 			ans.WriteString(";")
diff --git a/tools/tui/loop/terminal-state.go b/tools/tui/loop/terminal-state.go
index c3e7ad616..c0b35b0c3 100644
--- a/tools/tui/loop/terminal-state.go
+++ b/tools/tui/loop/terminal-state.go
@@ -159,7 +159,7 @@ func (self *TerminalStateOptions) SetStateEscapeCodes() string {
 		sb.WriteString("\033[>u")
 	case NO_KEYBOARD_STATE_CHANGE:
 	default:
-		sb.WriteString(fmt.Sprintf("\033[>%du", self.kitty_keyboard_mode))
+		fmt.Fprintf(sb, "\033[>%du", self.kitty_keyboard_mode)
 	}
 	if self.mouse_tracking != NO_MOUSE_TRACKING {
 		sb.WriteString(MOUSE_SGR_PIXEL_MODE.EscapeCodeToSet())