diff --git a/mysql-test/r/date_formats.result b/mysql-test/r/date_formats.result
index edfe17b0cb4..24abdfcf148 100644
--- a/mysql-test/r/date_formats.result
+++ b/mysql-test/r/date_formats.result
@@ -491,3 +491,21 @@ TIME_FORMAT("01:00:00", '%r')
 SELECT TIME_FORMAT("25:00:00", '%r');
 TIME_FORMAT("25:00:00", '%r')
 01:00:00 AM
+SELECT TIME_FORMAT("00:00:00", '%l %p');
+TIME_FORMAT("00:00:00", '%l %p')
+12 AM
+SELECT TIME_FORMAT("01:00:00", '%l %p');
+TIME_FORMAT("01:00:00", '%l %p')
+1 AM
+SELECT TIME_FORMAT("12:00:00", '%l %p');
+TIME_FORMAT("12:00:00", '%l %p')
+12 PM
+SELECT TIME_FORMAT("23:00:00", '%l %p');
+TIME_FORMAT("23:00:00", '%l %p')
+11 PM
+SELECT TIME_FORMAT("24:00:00", '%l %p');
+TIME_FORMAT("24:00:00", '%l %p')
+12 AM
+SELECT TIME_FORMAT("25:00:00", '%l %p');
+TIME_FORMAT("25:00:00", '%l %p')
+1 AM
diff --git a/mysql-test/t/date_formats.test b/mysql-test/t/date_formats.test
index 143cddbc4fe..f3d507e69e6 100644
--- a/mysql-test/t/date_formats.test
+++ b/mysql-test/t/date_formats.test
@@ -287,3 +287,14 @@ SELECT TIME_FORMAT("12:00:00", '%r');
 SELECT TIME_FORMAT("15:00:00", '%r');
 SELECT TIME_FORMAT("01:00:00", '%r');
 SELECT TIME_FORMAT("25:00:00", '%r');
+
+#
+# Bug#11324
+#
+
+SELECT TIME_FORMAT("00:00:00", '%l %p');
+SELECT TIME_FORMAT("01:00:00", '%l %p');
+SELECT TIME_FORMAT("12:00:00", '%l %p');
+SELECT TIME_FORMAT("23:00:00", '%l %p');
+SELECT TIME_FORMAT("24:00:00", '%l %p');
+SELECT TIME_FORMAT("25:00:00", '%l %p');
diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index f26b5aae37a..670fb94fc2c 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -609,7 +609,7 @@ bool make_date_time(DATE_TIME_FORMAT *format, TIME *l_time,
 	break;
       case 'l':
 	days_i= l_time->hour/24;
-	hours_i= (l_time->hour%24 + 11)%12+1 + 24*days_i;
+	hours_i= (l_time->hour%24 + 11)%12+1;
 	length= int10_to_str(hours_i, intbuff, 10) - intbuff;
 	str->append_with_prefill(intbuff, length, 1, '0');
 	break;