diff --git a/src/db.c b/src/db.c
index 71c642d0..4d6999be 100644
--- a/src/db.c
+++ b/src/db.c
@@ -38,6 +38,15 @@
  * C-level DB API
  *----------------------------------------------------------------------------*/
 
+/* Update LFU when an object is accessed.
+ * Firstly, decrement the counter if the decrement time is reached.
+ * Then logarithmically increment the counter, and update the access time. */
+void updateLFU(robj *val) {
+    unsigned long counter = LFUDecrAndReturn(val);
+    counter = LFULogIncr(counter);
+    val->lru = (LFUGetTimeInMinutes()<<8) | counter;
+}
+
 /* Low level key lookup API, not actually called directly from commands
  * implementations that should instead rely on lookupKeyRead(),
  * lookupKeyWrite() and lookupKeyReadWithFlags(). */
@@ -54,9 +63,7 @@ robj *lookupKey(redisDb *db, robj *key, int flags) {
             !(flags & LOOKUP_NOTOUCH))
         {
             if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
-                unsigned long ldt = val->lru >> 8;
-                unsigned long counter = LFULogIncr(val->lru & 255);
-                val->lru = (ldt << 8) | counter;
+                updateLFU(val);
             } else {
                 val->lru = LRU_CLOCK();
             }
@@ -180,6 +187,9 @@ void dbOverwrite(redisDb *db, robj *key, robj *val) {
         int saved_lru = old->lru;
         dictReplace(db->dict, key->ptr, val);
         val->lru = saved_lru;
+        /* LFU should be not only copied but also updated
+         * when a key is overwritten. */
+        updateLFU(val);
     } else {
         dictReplace(db->dict, key->ptr, val);
     }
diff --git a/src/evict.c b/src/evict.c
index 0a04ed1b..55b13212 100644
--- a/src/evict.c
+++ b/src/evict.c
@@ -60,8 +60,6 @@ struct evictionPoolEntry {
 
 static struct evictionPoolEntry *EvictionPoolLRU;
 
-unsigned long LFUDecrAndReturn(robj *o);
-
 /* ----------------------------------------------------------------------------
  * Implementation of eviction, aging and LRU
  * --------------------------------------------------------------------------*/
@@ -302,8 +300,8 @@ unsigned long LFUGetTimeInMinutes(void) {
     return (server.unixtime/60) & 65535;
 }
 
-/* Given an object last decrement time, compute the minimum number of minutes
- * that elapsed since the last decrement. Handle overflow (ldt greater than
+/* Given an object last access time, compute the minimum number of minutes
+ * that elapsed since the last access. Handle overflow (ldt greater than
  * the current 16 bits minutes time) considering the time as wrapping
  * exactly once. */
 unsigned long LFUTimeElapsed(unsigned long ldt) {
@@ -324,24 +322,31 @@ uint8_t LFULogIncr(uint8_t counter) {
     return counter;
 }
 
-/* If the object decrement time is reached, decrement the LFU counter and
- * update the decrement time field. Return the object frequency counter.
+/* If the object decrement time is reached decrement the LFU counter but
+ * do not update LFU fields of the object, we update the access time
+ * and counter in an explicit way when the object is really accessed.
+ * And we will times halve the counter according to the times of
+ * elapsed time than server.lfu_decay_time.
+ * Return the object frequency counter.
  *
  * This function is used in order to scan the dataset for the best object
  * to fit: as we check for the candidate, we incrementally decrement the
  * counter of the scanned objects if needed. */
-#define LFU_DECR_INTERVAL 1
 unsigned long LFUDecrAndReturn(robj *o) {
     unsigned long ldt = o->lru >> 8;
     unsigned long counter = o->lru & 255;
-    if (LFUTimeElapsed(ldt) >= (unsigned long)server.lfu_decay_time && counter) {
-        if (counter > LFU_INIT_VAL*2) {
-            counter /= 2;
-            if (counter < LFU_INIT_VAL*2) counter = LFU_INIT_VAL*2;
+    long halve_times = server.lfu_decay_time ? LFUTimeElapsed(ldt) / server.lfu_decay_time : 0;
+    if (halve_times > 0 && counter) {
+        if (halve_times == 1) {
+            if (counter > LFU_INIT_VAL*2) {
+                counter /= 2;
+                if (counter < LFU_INIT_VAL*2) counter = LFU_INIT_VAL*2;
+            } else {
+                counter--;
+            }
         } else {
-            counter--;
+            counter = counter >> halve_times;
         }
-        o->lru = (LFUGetTimeInMinutes()<<8) | counter;
     }
     return counter;
 }
diff --git a/src/object.c b/src/object.c
index 8c33d7ef..d2f8d53c 100644
--- a/src/object.c
+++ b/src/object.c
@@ -1050,10 +1050,14 @@ void objectCommand(client *c) {
         if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
                 == NULL) return;
         if (!(server.maxmemory_policy & MAXMEMORY_FLAG_LFU)) {
-            addReplyError(c,"A non-LFU maxmemory policy is selected, access frequency not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
+            addReplyError(c,"An LFU maxmemory policy is not selected, access frequency not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
             return;
         }
-        addReplyLongLong(c,o->lru&255);
+        /* LFUDecrAndReturn should be called
+         * in case of the key has not been accessed for a long time,
+         * because we update the access time only
+         * when the key is read or overwritten. */
+        addReplyLongLong(c,LFUDecrAndReturn(o));
     } else {
         addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try OBJECT help",
             (char *)c->argv[1]->ptr);
diff --git a/src/server.h b/src/server.h
index aa04344c..9b7da1d3 100644
--- a/src/server.h
+++ b/src/server.h
@@ -586,7 +586,7 @@ typedef struct redisObject {
     unsigned encoding:4;
     unsigned lru:LRU_BITS; /* LRU time (relative to global lru_clock) or
                             * LFU data (least significant 8 bits frequency
-                            * and most significant 16 bits decreas time). */
+                            * and most significant 16 bits access time). */
     int refcount;
     void *ptr;
 } robj;
@@ -1802,6 +1802,7 @@ void evictionPoolAlloc(void);
 #define LFU_INIT_VAL 5
 unsigned long LFUGetTimeInMinutes(void);
 uint8_t LFULogIncr(uint8_t value);
+unsigned long LFUDecrAndReturn(robj *o);
 
 /* Keys hashing / comparison functions for dict.c hash tables. */
 uint64_t dictSdsHash(const void *key);