diff --git a/src/captcha/image.py b/src/captcha/image.py
index ecc43f7..84de254 100644
--- a/src/captcha/image.py
+++ b/src/captcha/image.py
@@ -103,7 +103,10 @@ class ImageCaptcha:
             draw: ImageDraw,
             color: ColorTuple) -> Image:
         font = random.choice(self.truefonts)
-        _, _, w, h = draw.textbbox((1, 1), c, font=font)
+
+        left, top, right, bottom = draw.textbbox((0, 0), c, font=font)
+        w = int((right - left)*1.7) or 1
+        h = int((bottom - top)*1.7) or 1
 
         dx1 = random.randint(0, 4)
         dy1 = random.randint(0, 6)