diff --git a/libril/ril.cpp b/libril/ril.cpp
index 52d574d..514ac90 100644
--- a/libril/ril.cpp
+++ b/libril/ril.cpp
@@ -285,6 +285,13 @@
         int responseType = (s_callbacks.version >= 13)
                            ? RESPONSE_UNSOLICITED_ACK_EXP
                            : RESPONSE_UNSOLICITED;
+        // acquire read lock for the service before calling nitzTimeReceivedInd() since it reads
+        // nitzTimeReceived in ril_service
+        pthread_rwlock_t *radioServiceRwlockPtr = radio::getRadioServiceRwlock(
+                (int) socket_id);
+        int rwlockRet = pthread_rwlock_rdlock(radioServiceRwlockPtr);
+        assert(rwlockRet == 0);
+
         int ret = radio::nitzTimeReceivedInd(
             (int)socket_id, responseType, 0,
             RIL_E_SUCCESS, s_lastNITZTimeData, s_lastNITZTimeDataSize);
@@ -292,6 +299,9 @@
             free(s_lastNITZTimeData);
             s_lastNITZTimeData = NULL;
         }
+
+        rwlockRet = pthread_rwlock_unlock(radioServiceRwlockPtr);
+        assert(rwlockRet == 0);
     }
 }
 
@@ -770,8 +780,17 @@
     }
 
     pthread_rwlock_t *radioServiceRwlockPtr = radio::getRadioServiceRwlock((int) soc_id);
-    int rwlockRet = pthread_rwlock_rdlock(radioServiceRwlockPtr);
-    assert(rwlockRet == 0);
+    int rwlockRet;
+
+    if (unsolResponse == RIL_UNSOL_NITZ_TIME_RECEIVED) {
+        // get a write lock in caes of NITZ since setNitzTimeReceived() is called
+        rwlockRet = pthread_rwlock_wrlock(radioServiceRwlockPtr);
+        assert(rwlockRet == 0);
+        radio::setNitzTimeReceived((int) soc_id, android::elapsedRealtime());
+    } else {
+        rwlockRet = pthread_rwlock_rdlock(radioServiceRwlockPtr);
+        assert(rwlockRet == 0);
+    }
 
     ret = s_unsolResponses[unsolResponseIndex].responseFunction(
             (int) soc_id, responseType, 0, RIL_E_SUCCESS, const_cast<void*>(data),
diff --git a/libril/ril_service.cpp b/libril/ril_service.cpp
index 9b9b641..d90ba9c 100644
--- a/libril/ril_service.cpp
+++ b/libril/ril_service.cpp
@@ -69,12 +69,14 @@
 #if (SIM_COUNT >= 2)
 sp<RadioImpl> radioService[SIM_COUNT];
 sp<OemHookImpl> oemHookService[SIM_COUNT];
+int64_t nitzTimeReceived[SIM_COUNT];
 // counter used for synchronization. It is incremented every time response callbacks are updated.
 volatile int32_t mCounterRadio[SIM_COUNT];
 volatile int32_t mCounterOemHook[SIM_COUNT];
 #else
 sp<RadioImpl> radioService[1];
 sp<OemHookImpl> oemHookService[1];
+int64_t nitzTimeReceived[1];
 // counter used for synchronization. It is incremented every time response callbacks are updated.
 volatile int32_t mCounterRadio[1];
 volatile int32_t mCounterOemHook[1];
@@ -6977,13 +6979,13 @@
             return 0;
         }
         hidl_string nitzTime = convertCharPtrToHidlString((char *) response);
-        int64_t timeReceived = android::elapsedRealtime();
 #if VDBG
         RLOGD("nitzTimeReceivedInd: nitzTime %s receivedTime %" PRId64, nitzTime.c_str(),
-                timeReceived);
+                nitzTimeReceived[slotId]);
 #endif
         Return<void> retStatus = radioService[slotId]->mRadioIndication->nitzTimeReceived(
-                convertIntToRadioIndicationType(indicationType), nitzTime, timeReceived);
+                convertIntToRadioIndicationType(indicationType), nitzTime,
+                nitzTimeReceived[slotId]);
         radioService[slotId]->checkReturnStatus(retStatus);
     } else {
         RLOGE("nitzTimeReceivedInd: radioService[%d]->mRadioIndication == NULL", slotId);
@@ -8528,3 +8530,8 @@
 
     return radioServiceRwlockPtr;
 }
+
+// should acquire write lock for the corresponding service before calling this
+void radio::setNitzTimeReceived(int slotId, long timeReceived) {
+    nitzTimeReceived[slotId] = timeReceived;
+}
diff --git a/libril/ril_service.h b/libril/ril_service.h
index 2240e2a..870b644 100644
--- a/libril/ril_service.h
+++ b/libril/ril_service.h
@@ -743,6 +743,8 @@
 
 pthread_rwlock_t * getRadioServiceRwlock(int slotId);
 
+void setNitzTimeReceived(int slotId, long timeReceived);
+
 }   // namespace radio
 
 #endif  // RIL_SERVICE_H