diff --git a/src/reader.rs b/src/reader.rs
index 77671a132..2c8b79ce0 100644
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -2795,7 +2795,7 @@ impl ReaderData {
                 let mut capitalized_first = false;
 
                 // We apply the operation from the current location to the end of the word.
-                let pos = el.position();
+                let mut pos = el.position();
                 let init_pos = pos;
                 self.move_word(
                     elt,
@@ -2824,6 +2824,7 @@ impl ReaderData {
                         replacement.extend(chr.to_lowercase());
                     };
                     capitalized_first = capitalized_first || make_uppercase;
+                    pos = pos + 1;
                 }
                 self.replace_substring(elt, init_pos..pos, replacement);
                 self.update_buff_pos(elt, None);
diff --git a/tests/pexpects/bind.py b/tests/pexpects/bind.py
index 9d9e57707..67bac5286 100644
--- a/tests/pexpects/bind.py
+++ b/tests/pexpects/bind.py
@@ -375,6 +375,11 @@ expect_prompt()
 send("\x1A")
 expect_str("bound ctrl-z")
 
+send('echo foobar')
+send('\x02\x02\x02') # ctrl-b, backward-char
+sendline('\x1bu') # alt+u, upcase word
+expect_prompt("fooBAR")
+
 # Check that the builtin version of `exit` works
 # (for obvious reasons this MUST BE LAST)
 sendline("function myexit; echo exit; exit; end; bind \cz myexit")