diff --git a/Lib/idlelib/HyperParser.py b/Lib/idlelib/HyperParser.py
index 38a19f2..4414de7 100644
--- a/Lib/idlelib/HyperParser.py
+++ b/Lib/idlelib/HyperParser.py
@@ -232,6 +232,11 @@
                     pass
                 else:
                     # We can't continue after other types of brackets
+                    if rawtext[pos] in "'\"":
+                        # Scan a string prefix
+                        while pos > 0 and rawtext[pos - 1] in "rRbB":
+                            pos -= 1
+                        last_identifier_pos = pos
                     break
 
             else:
diff --git a/Misc/NEWS b/Misc/NEWS
index a7e2534..b9b14a7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -189,6 +189,8 @@
 Library
 -------
 
+- Issue #16819: IDLE method completion now correctly works for bytes literals.
+
 - Issue #9586: Redefine SEM_FAILED on MacOSX to keep compiler happy.
 
 - Issue 10527: make multiprocessing use poll() instead of select() if available.