diff --git a/CHANGES b/CHANGES
index 7b7a3054fa..d62f23b00f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -25,6 +25,7 @@ Version 2.7.4
 - Lex trailing whitespace as part of the prompt in shell lexers (#1645)
 - Add missing ONLY keyword to Fortran (#1635)
 - Add missing regex flags to JS/TS/... lexers (#1647)
+- Add missing ``in`` keyword to shell (#1652)
 
 Thanks to Google's OSS-Fuzz project for finding many of these bugs.
 
diff --git a/pygments/lexers/shell.py b/pygments/lexers/shell.py
index daef1f39ac..e9dd379681 100644
--- a/pygments/lexers/shell.py
+++ b/pygments/lexers/shell.py
@@ -57,7 +57,7 @@ class BashLexer(RegexLexer):
             (r'\$', Text),
         ],
         'basic': [
-            (r'\b(if|fi|else|while|do|done|for|then|return|function|case|'
+            (r'\b(if|fi|else|while|in|do|done|for|then|return|function|case|'
              r'select|continue|until|esac|elif)(\s*)\b',
              bygroups(Keyword, Text)),
             (r'\b(alias|bg|bind|break|builtin|caller|cd|command|compgen|'