diff --git a/src/reader.cpp b/src/reader.cpp
index d07af18a9..b361cccfc 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -2790,7 +2790,19 @@ void reader_data_t::handle_readline_command(readline_cmd_t c, readline_loop_stat
             break;
         }
         case rl::cancel: {
-            // The only thing we can cancel right now is paging, which we handled up above.
+            // If we last inserted a completion, undo it.
+            // This doesn't apply if the completion was selected via the pager
+            // (in which case the last command is "execute" or similar,
+            // but never complete{,_and_search})
+            //
+            // Also paging is already cancelled above.
+            if (rls.complete_did_insert &&
+                (rls.last_cmd == rl::complete
+                 || rls.last_cmd == rl::complete_and_search)) {
+                editable_line_t *el = active_edit_line();
+                el->undo();
+                update_buff_pos(el);
+            }
             break;
         }
         case rl::repaint_mode: {
diff --git a/tests/pexpects/complete.py b/tests/pexpects/complete.py
index 0324c365e..6815bb657 100644
--- a/tests/pexpects/complete.py
+++ b/tests/pexpects/complete.py
@@ -13,6 +13,8 @@ expect_prompt()
 
 sendline(
     """
+    # Make sure this function does nothing
+    function my_is; :; end
     complete -c my_is -n 'test (count (commandline -opc)) = 1' -xa arg
     complete -c my_is -n '__fish_seen_subcommand_from not' -xa '(
 	set -l cmd (commandline -opc) (commandline -ct)
@@ -26,3 +28,23 @@ sendline(
 send("my_is not \t")
 send("still.alive")
 expect_re(".*still.alive")
+sendline("")
+
+# Check cancelling completion acceptance
+# (bind cancel to something else so we don't have to mess with the escape delay)
+sendline("bind \cg cancel")
+sendline("complete -c echo -x -a 'foooo bar'")
+send("echo fo\t")
+send("\x07")
+sendline("bar")
+expect_re("bar")
+sendline("echo fo\t")
+expect_re("foooo")
+
+# As soon as something after the "complete" happened,
+# cancel should not undo.
+# In this case that's the space after the tab!
+send("echo fo\t ")
+send("\x07")
+sendline("bar")
+expect_re("foooo bar")