diff --git a/src/core/iomgr/timer.c b/src/core/iomgr/timer.c
index 1bf8387d74b..8379fffad02 100644
--- a/src/core/iomgr/timer.c
+++ b/src/core/iomgr/timer.c
@@ -41,7 +41,7 @@
 
 #define INVALID_HEAP_INDEX 0xffffffffu
 
-#define LOG2_NUM_SHARDS 2
+#define LOG2_NUM_SHARDS 5
 #define NUM_SHARDS (1 << LOG2_NUM_SHARDS)
 #define ADD_DEADLINE_SCALE 0.33
 #define MIN_QUEUE_WINDOW_DURATION 0.01