diff --git a/vlib/math/big/integer.v b/vlib/math/big/integer.v
index 3762cf6f1a..5a8e342c99 100644
--- a/vlib/math/big/integer.v
+++ b/vlib/math/big/integer.v
@@ -175,7 +175,7 @@ pub fn integer_from_radix(all_characters string, radix u32) !Integer {
 		return error('math.big: Radix must be between 2 and 36 (inclusive)')
 	}
 	characters := all_characters.to_lower()
-	validate_string(characters, radix)!
+	validate_string(characters, radix) or { return err }
 	return match radix {
 		2 {
 			integer_from_special_string(characters, 1)