diff --git a/History.md b/History.md
index a7a2bb8884..8da6385cc8 100644
--- a/History.md
+++ b/History.md
@@ -1,10 +1,7 @@
 ## Master
 
-* Features
-  * Your feature goes here (#Github Number)
-
 * Bugfixes
-  * Your bugfix goes here (#Github Number)
+  * Explicitly include ctype.h to fix compilation warning and build error on macOS with Xcode 12 (#2304)
 
 ## 4.3.4/4.3.5 and 3.12.5/3.12.6 / 2020-05-22
 
diff --git a/ext/puma_http11/puma_http11.c b/ext/puma_http11/puma_http11.c
index 7ac1b478b5..1c1c3b944e 100644
--- a/ext/puma_http11/puma_http11.c
+++ b/ext/puma_http11/puma_http11.c
@@ -10,6 +10,7 @@
 #include "ext_help.h"
 #include <assert.h>
 #include <string.h>
+#include <ctype.h>
 #include "http11_parser.h"
 
 #ifndef MANAGED_STRINGS