diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 4ad6b3d..b69f6b4 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -8158,7 +8158,7 @@
 <		      1.41
 
 		You will get an overflow error |E1510|, when the field-width
-		or precision will result in a string longer than 1 MB
+		or precision will result in a string longer than 1 MiB
 		(1024*1024 = 1048576) chars.
 
 							*E1500*