diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index bb63dbd5303..4bf870eb7ce 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -269,7 +269,7 @@ impl<'a> StringReader<'a> {
                 // as there will be less overall work to do this way.
                 let token = unicode_chars::check_for_substitution(self, start, c, &mut err);
                 if c == '\x00' {
-                    err.help("source files must be encoded in UTF-8, unexpected null bytes might occur when the wrong text encoding is used");
+                    err.help("source files must contain UTF-8 encoded text, unexpected null bytes might occur when a different encoding is used");
                 }
                 err.emit();
                 token?