diff --git a/android/jni/com/mapswithme/maps/DownloadResourcesLegacyActivity.cpp b/android/jni/com/mapswithme/maps/DownloadResourcesLegacyActivity.cpp
index 9fa1192851..cbd9772202 100644
--- a/android/jni/com/mapswithme/maps/DownloadResourcesLegacyActivity.cpp
+++ b/android/jni/com/mapswithme/maps/DownloadResourcesLegacyActivity.cpp
@@ -75,7 +75,7 @@ extern "C"
         return ERR_NOT_ENOUGH_FREE_SPACE;
 
       default:
-        return fileSize;
+        return static_cast<int>(fileSize);
     }
   }
 
diff --git a/android/jni/com/mapswithme/maps/Framework.cpp b/android/jni/com/mapswithme/maps/Framework.cpp
index 1691fa9750..9953328a7d 100644
--- a/android/jni/com/mapswithme/maps/Framework.cpp
+++ b/android/jni/com/mapswithme/maps/Framework.cpp
@@ -1355,20 +1355,24 @@ Java_com_mapswithme_maps_Framework_nativeGetRouteFollowingInfo(JNIEnv * env, jcl
   {
     static jclass const laneClass = jni::GetGlobalClassRef(env, "com/mapswithme/maps/routing/SingleLaneInfo");
     size_t const lanesSize = lanes.size();
-    jLanes = env->NewObjectArray(lanesSize, laneClass, nullptr);
+    jLanes = env->NewObjectArray(static_cast<jsize>(lanesSize), laneClass, nullptr);
     ASSERT(jLanes, (jni::DescribeException()));
     static jmethodID const ctorSingleLaneInfoID = jni::GetConstructorID(env, laneClass, "([BZ)V");
 
     for (size_t j = 0; j < lanesSize; ++j)
     {
       size_t const laneSize = lanes[j].m_lane.size();
-      jni::TScopedLocalByteArrayRef singleLane(env, env->NewByteArray(laneSize));
+      jni::TScopedLocalByteArrayRef singleLane(env,
+                                               env->NewByteArray(static_cast<jsize>(laneSize)));
       ASSERT(singleLane.get(), (jni::DescribeException()));
-      env->SetByteArrayRegion(singleLane.get(), 0, laneSize, lanes[j].m_lane.data());
+      env->SetByteArrayRegion(singleLane.get(), 0, static_cast<jsize>(laneSize),
+                              lanes[j].m_lane.data());
 
-      jni::TScopedLocalRef singleLaneInfo(env, env->NewObject(laneClass, ctorSingleLaneInfoID, singleLane.get(), lanes[j].m_isRecommended));
+      jni::TScopedLocalRef singleLaneInfo(
+          env, env->NewObject(laneClass, ctorSingleLaneInfoID, singleLane.get(),
+                              lanes[j].m_isRecommended));
       ASSERT(singleLaneInfo.get(), (jni::DescribeException()));
-      env->SetObjectArrayElement(jLanes, j, singleLaneInfo.get());
+      env->SetObjectArrayElement(jLanes, static_cast<jsize>(j), singleLaneInfo.get());
     }
   }
 
@@ -1447,7 +1451,7 @@ Java_com_mapswithme_maps_Framework_nativeGenerateRouteAltitudeChartBits(JNIEnv *
     return nullptr;
   }
 
-  jintArray imageRGBADataArray = env->NewIntArray(pxlCount);
+  jintArray imageRGBADataArray = env->NewIntArray(static_cast<jsize>(pxlCount));
   ASSERT(imageRGBADataArray, ());
   jint * arrayElements = env->GetIntArrayElements(imageRGBADataArray, 0);
   ASSERT(arrayElements, ());
diff --git a/android/jni/com/mapswithme/maps/MapManager.cpp b/android/jni/com/mapswithme/maps/MapManager.cpp
index a62046f81c..eae3f91572 100644
--- a/android/jni/com/mapswithme/maps/MapManager.cpp
+++ b/android/jni/com/mapswithme/maps/MapManager.cpp
@@ -238,7 +238,7 @@ Java_com_mapswithme_maps_downloader_MapManager_nativeCancelMigration(JNIEnv * en
 JNIEXPORT jint JNICALL
 Java_com_mapswithme_maps_downloader_MapManager_nativeGetDownloadedCount(JNIEnv * env, jclass clazz)
 {
-  return GetStorage().GetDownloadedFilesCount();
+  return static_cast<jint>(GetStorage().GetDownloadedFilesCount());
 }
 
 // static @Nullable UpdateInfo nativeGetUpdateInfo(@Nullable String root);
diff --git a/android/jni/com/mapswithme/maps/SearchEngine.cpp b/android/jni/com/mapswithme/maps/SearchEngine.cpp
index 43b8d66659..400e299ff4 100644
--- a/android/jni/com/mapswithme/maps/SearchEngine.cpp
+++ b/android/jni/com/mapswithme/maps/SearchEngine.cpp
@@ -294,7 +294,8 @@ jobject ToJavaResult(Result & result, search::ProductInfo const & productInfo, b
 {
   JNIEnv * env = jni::GetEnv();
 
-  jni::TScopedLocalIntArrayRef ranges(env, env->NewIntArray(result.GetHighlightRangesCount() * 2));
+  jni::TScopedLocalIntArrayRef ranges(
+      env, env->NewIntArray(static_cast<jsize>(result.GetHighlightRangesCount() * 2)));
   jint * rawArr = env->GetIntArrayElements(ranges, nullptr);
   for (int i = 0; i < result.GetHighlightRangesCount(); i++)
   {
@@ -402,14 +403,15 @@ jobjectArray BuildJavaMapResults(vector<storage::DownloaderSearchResult> const &
 {
   JNIEnv * env = jni::GetEnv();
 
-  int const count = results.size();
-  jobjectArray const res = env->NewObjectArray(count, g_mapResultClass, nullptr);
-  for (int i = 0; i < count; i++)
+  size_t const count = results.size();
+  jobjectArray const res =
+      env->NewObjectArray(static_cast<jsize>(count), g_mapResultClass, nullptr);
+  for (size_t i = 0; i < count; i++)
   {
     jni::TScopedLocalRef country(env, jni::ToJavaString(env, results[i].m_countryId));
     jni::TScopedLocalRef matched(env, jni::ToJavaString(env, results[i].m_matchedName));
     jni::TScopedLocalRef item(env, env->NewObject(g_mapResultClass, g_mapResultCtor, country.get(), matched.get()));
-    env->SetObjectArrayElement(res, i, item.get());
+    env->SetObjectArrayElement(res, static_cast<jsize>(i), item.get());
   }
 
   return res;
@@ -443,9 +445,10 @@ void OnBookmarksSearchResults(search::BookmarksSearchParams::Results const & res
 
   auto filteredResults = results;
   g_framework->NativeFramework()->GetBookmarkManager().FilterInvalidBookmarks(filteredResults);
-  jni::ScopedLocalRef<jlongArray> jResults(env, env->NewLongArray(filteredResults.size()));
+  jni::ScopedLocalRef<jlongArray> jResults(
+      env, env->NewLongArray(static_cast<jsize>(filteredResults.size())));
   vector<jlong> const tmp(filteredResults.cbegin(), filteredResults.cend());
-  env->SetLongArrayRegion(jResults.get(), 0, tmp.size(), tmp.data());
+  env->SetLongArrayRegion(jResults.get(), 0, static_cast<jsize>(tmp.size()), tmp.data());
 
   auto const method = (status == search::BookmarksSearchParams::Status::InProgress) ?
                       g_updateBookmarksResultsId : g_endBookmarksResultsId;
@@ -525,10 +528,12 @@ public:
       return result;
 
     jlong const jcheckin = env->GetLongField(bookingFilterParams, m_checkinMillisecId) / 1000;
-    result.m_checkin = booking::AvailabilityParams::Clock::from_time_t(jcheckin);
+    result.m_checkin =
+        booking::AvailabilityParams::Clock::from_time_t(static_cast<time_t>(jcheckin));
 
     jlong const jcheckout = env->GetLongField(bookingFilterParams, m_checkoutMillisecId) / 1000;
-    result.m_checkout = booking::AvailabilityParams::Clock::from_time_t(jcheckout);
+    result.m_checkout =
+        booking::AvailabilityParams::Clock::from_time_t(static_cast<time_t>(jcheckout));
 
     jobjectArray const jrooms =
         static_cast<jobjectArray>(env->GetObjectField(bookingFilterParams, m_roomsId));
@@ -538,7 +543,7 @@ public:
     result.m_rooms.resize(length);
     for (size_t i = 0; i < length; ++i)
     {
-      jobject jroom = env->GetObjectArrayElement(jrooms, i);
+      jobject jroom = env->GetObjectArrayElement(jrooms, static_cast<jsize>(i));
 
       booking::AvailabilityParams::Room room;
       room.SetAdultsCount(static_cast<uint8_t>(env->GetIntField(jroom, m_roomAdultsCountId)));
@@ -619,14 +624,15 @@ jobjectArray BuildSearchResults(Results const & results,
 
   g_results = results;
 
-  int const count = g_results.GetCount();
-  jobjectArray const jResults = env->NewObjectArray(count, g_resultClass, nullptr);
+  size_t const count = g_results.GetCount();
+  jobjectArray const jResults =
+      env->NewObjectArray(static_cast<jsize>(count), g_resultClass, nullptr);
 
-  for (int i = 0; i < count; i++)
+  for (size_t i = 0; i < count; i++)
   {
     jni::TScopedLocalRef jRes(env,
                               ToJavaResult(g_results[i], productInfo[i], hasPosition, lat, lon));
-    env->SetObjectArrayElement(jResults, i, jRes.get());
+    env->SetObjectArrayElement(jResults, static_cast<jsize>(i), jRes.get());
   }
   return jResults;
 }
diff --git a/android/jni/com/mapswithme/maps/Sponsored.cpp b/android/jni/com/mapswithme/maps/Sponsored.cpp
index 8e39e92c14..0e9eb09b09 100644
--- a/android/jni/com/mapswithme/maps/Sponsored.cpp
+++ b/android/jni/com/mapswithme/maps/Sponsored.cpp
@@ -173,8 +173,8 @@ JNIEXPORT void JNICALL Java_com_mapswithme_maps_widget_placepage_Sponsored_nativ
                                                    jni::ToJavaString(env, hotelId),
                                                    jni::ToJavaString(env, price),
                                                    jni::ToJavaString(env, blocks.m_currency),
-                                                   static_cast<jint>(env, blocks.m_maxDiscount),
-                                                   static_cast<jboolean>(env, blocks.m_hasSmartDeal));
+                                                   static_cast<jint>(blocks.m_maxDiscount),
+                                                   static_cast<jboolean>(blocks.m_hasSmartDeal));
 
         env->CallStaticVoidMethod(g_sponsoredClass, g_priceCallback, hotelPriceInfo);
       });
diff --git a/android/jni/com/mapswithme/maps/TrackRecorder.cpp b/android/jni/com/mapswithme/maps/TrackRecorder.cpp
index be39741948..d595f3a05e 100644
--- a/android/jni/com/mapswithme/maps/TrackRecorder.cpp
+++ b/android/jni/com/mapswithme/maps/TrackRecorder.cpp
@@ -44,6 +44,6 @@ extern "C"
   JNIEXPORT jint JNICALL
   Java_com_mapswithme_maps_location_TrackRecorder_nativeGetDuration(JNIEnv * env, jclass clazz)
   {
-    return GpsTracker::Instance().GetDuration().count();
+    return static_cast<jint>(GpsTracker::Instance().GetDuration().count());
   }
 }
diff --git a/android/jni/com/mapswithme/maps/UserMarkHelper.cpp b/android/jni/com/mapswithme/maps/UserMarkHelper.cpp
index 86cbf90dc6..e4ee3d1d67 100644
--- a/android/jni/com/mapswithme/maps/UserMarkHelper.cpp
+++ b/android/jni/com/mapswithme/maps/UserMarkHelper.cpp
@@ -265,14 +265,13 @@ jintArray ToReachableByTaxiProvidersArray(JNIEnv * env, std::vector<taxi::Provid
   if (types.size() == 0)
     return nullptr;
 
-  jintArray result = env->NewIntArray(types.size());
-  ASSERT(result, ());
-
   jint tmp[types.size()];
-  for (int i = 0; i < types.size(); i++)
+  for (size_t i = 0; i < types.size(); ++i)
     tmp[i] = static_cast<jint>(types[i]);
 
-  env->SetIntArrayRegion(result, 0, types.size(), tmp);
+  jintArray result = env->NewIntArray(static_cast<jsize>(types.size()));
+  ASSERT(result, ());
+  env->SetIntArrayRegion(result, 0, static_cast<jsize>(types.size()), tmp);
 
   return result;
 }
diff --git a/android/jni/com/mapswithme/maps/editor/Editor.cpp b/android/jni/com/mapswithme/maps/editor/Editor.cpp
index 5ef5b6e47a..e5a59d29e6 100644
--- a/android/jni/com/mapswithme/maps/editor/Editor.cpp
+++ b/android/jni/com/mapswithme/maps/editor/Editor.cpp
@@ -264,10 +264,10 @@ JNIEXPORT jintArray JNICALL
 Java_com_mapswithme_maps_editor_Editor_nativeGetEditableFields(JNIEnv * env, jclass clazz)
 {
   auto const & editable = g_editableMapObject.GetEditableFields();
-  int const size = editable.size();
-  jintArray jEditableFields = env->NewIntArray(size);
+  size_t const size = editable.size();
+  jintArray jEditableFields = env->NewIntArray(static_cast<jsize>(size));
   jint * arr = env->GetIntArrayElements(jEditableFields, 0);
-  for (int i = 0; i < size; ++i)
+  for (size_t i = 0; i < size; ++i)
     arr[i] = editable[i];
   env->ReleaseIntArrayElements(jEditableFields, arr, 0);
 
@@ -304,7 +304,7 @@ Java_com_mapswithme_maps_editor_Editor_nativeGetNamesDataSource(JNIEnv * env, jc
   auto const namesDataSource = g_editableMapObject.GetNamesDataSource(needFakes);
 
   jobjectArray names = jni::ToJavaArray(env, g_localNameClazz, namesDataSource.names, ToJavaName);
-  jint mandatoryNamesCount = namesDataSource.mandatoryNamesCount;
+  jsize const mandatoryNamesCount = static_cast<jsize>(namesDataSource.mandatoryNamesCount);
 
   return env->NewObject(g_namesDataSourceClassID, g_namesDataSourceConstructorID, names, mandatoryNamesCount);
 }
diff --git a/android/jni/com/mapswithme/maps/editor/OpeningHours.cpp b/android/jni/com/mapswithme/maps/editor/OpeningHours.cpp
index 55faa9f909..e943246f02 100644
--- a/android/jni/com/mapswithme/maps/editor/OpeningHours.cpp
+++ b/android/jni/com/mapswithme/maps/editor/OpeningHours.cpp
@@ -79,8 +79,9 @@ jobject JavaTimetable(JNIEnv * env, TimeTable const & tt)
   {
     return static_cast<int>(weekday);
   });
-  jintArray jWeekdays = env->NewIntArray(weekdays.size());
-  env->SetIntArrayRegion(jWeekdays, 0, weekdaysVector.size(), &weekdaysVector[0]);
+  jintArray jWeekdays = env->NewIntArray(static_cast<jsize>(weekdays.size()));
+  env->SetIntArrayRegion(jWeekdays, 0, static_cast<jsize>(weekdaysVector.size()),
+                         &weekdaysVector[0]);
 
   return JavaTimetable(env,
                        JavaTimespan(env, tt.GetOpeningTime()),
@@ -94,12 +95,12 @@ jobject JavaTimetable(JNIEnv * env, TimeTable const & tt)
 
 jobjectArray JavaTimetables(JNIEnv * env, TimeTableSet & tts)
 {
-  int const size = tts.Size();
-  jobjectArray const result = env->NewObjectArray(size, g_clazzTimetable, 0);
-  for (int i = 0; i < size; i++)
+  size_t const size = tts.Size();
+  jobjectArray const result = env->NewObjectArray(static_cast<jsize>(size), g_clazzTimetable, 0);
+  for (size_t i = 0; i < size; i++)
   {
     jni::TScopedLocalRef jTable(env, JavaTimetable(env, tts.Get(i)));
-    env->SetObjectArrayElement(result, i, jTable.get());
+    env->SetObjectArrayElement(result, static_cast<jsize>(i), jTable.get());
   }
 
   return result;
diff --git a/android/jni/com/mapswithme/maps/promo/Promo.cpp b/android/jni/com/mapswithme/maps/promo/Promo.cpp
index c91705f4d8..bfe3d09d85 100644
--- a/android/jni/com/mapswithme/maps/promo/Promo.cpp
+++ b/android/jni/com/mapswithme/maps/promo/Promo.cpp
@@ -165,9 +165,9 @@ Java_com_mapswithme_maps_promo_Promo_nativeRequestPoiGallery(JNIEnv * env, jclas
 {
   PrepareClassRefs(env);
   auto const point = MercatorBounds::FromLatLon(static_cast<double>(lat), static_cast<double>(lon));
-  int const size = env->GetArrayLength(tags);
+  jsize const size = env->GetArrayLength(tags);
   promo::Tags nativeTags;
-  for (size_t i = 0; i < size; ++i)
+  for (jsize i = 0; i < size; ++i)
   {
     auto tag = jni::ToNativeString(env, static_cast<jstring>(env->GetObjectArrayElement(tags, i)));
     nativeTags.emplace_back(std::move(tag));
diff --git a/android/jni/com/mapswithme/maps/ugc/UGC.cpp b/android/jni/com/mapswithme/maps/ugc/UGC.cpp
index 8f7041df64..8e4bf90994 100644
--- a/android/jni/com/mapswithme/maps/ugc/UGC.cpp
+++ b/android/jni/com/mapswithme/maps/ugc/UGC.cpp
@@ -167,11 +167,11 @@ private:
   jobjectArray ToJavaRatings(JNIEnv * env, std::vector<ugc::RatingRecord> const & ratings)
   {
     size_t const n = ratings.size();
-    jobjectArray result = env->NewObjectArray(n, g_ratingClazz, nullptr);
+    jobjectArray result = env->NewObjectArray(static_cast<jsize>(n), g_ratingClazz, nullptr);
     for (size_t i = 0; i < n; ++i)
     {
       jni::TScopedLocalRef rating(env, ToJavaRating(env, ratings[i]));
-      env->SetObjectArrayElement(result, i, rating.get());
+      env->SetObjectArrayElement(result, static_cast<jsize>(i), rating.get());
     }
     return result;
   }
@@ -179,11 +179,11 @@ private:
   jobjectArray ToJavaReviews(JNIEnv * env, std::vector<ugc::Review> const & reviews)
   {
     size_t const n = reviews.size();
-    jobjectArray result = env->NewObjectArray(n, m_reviewClass, nullptr);
+    jobjectArray result = env->NewObjectArray(static_cast<jsize>(n), m_reviewClass, nullptr);
     for (size_t i = 0; i < n; ++i)
     {
       jni::TScopedLocalRef review(env, ToJavaReview(env, reviews[i]));
-      env->SetObjectArrayElement(result, i, review.get());
+      env->SetObjectArrayElement(result, static_cast<jsize>(i), review.get());
     }
     return result;
   }
diff --git a/android/jni/com/mapswithme/platform/HttpThread.cpp b/android/jni/com/mapswithme/platform/HttpThread.cpp
index f523e07e9a..0245ee7363 100644
--- a/android/jni/com/mapswithme/platform/HttpThread.cpp
+++ b/android/jni/com/mapswithme/platform/HttpThread.cpp
@@ -29,7 +29,7 @@ public:
     static std::string const uniqueUserId = GetPlatform().UniqueClientId();
 
     jni::TScopedLocalByteArrayRef postBody(env, nullptr);
-    size_t const postBodySize = pb.size();
+    jsize const postBodySize = static_cast<jsize>(pb.size());
     if (postBodySize)
     {
       postBody.reset(env->NewByteArray(postBodySize));
@@ -93,7 +93,7 @@ Java_com_mapswithme_maps_downloader_ChunkTask_nativeOnWrite(JNIEnv * env, jclass
   bool ret = false;
   try
   {
-    ret = cb->OnWrite(beg, buf, size);
+    ret = cb->OnWrite(beg, buf, static_cast<jsize>(size));
   }
   catch (std::exception const & ex)
   {
@@ -108,6 +108,6 @@ JNIEXPORT void JNICALL
 Java_com_mapswithme_maps_downloader_ChunkTask_nativeOnFinish(JNIEnv * env, jclass clazz, jlong httpCallbackID, jlong httpCode, jlong beg, jlong end)
 {
   downloader::IHttpThreadCallback * cb = reinterpret_cast<downloader::IHttpThreadCallback*>(httpCallbackID);
-  cb->OnFinish(httpCode, beg, end);
+  cb->OnFinish(static_cast<long>(httpCode), beg, end);
 }
 } // extern "C"
diff --git a/android/jni/com/mapswithme/util/HttpClient.cpp b/android/jni/com/mapswithme/util/HttpClient.cpp
index aa1f0514e0..71aa2a808c 100644
--- a/android/jni/com/mapswithme/util/HttpClient.cpp
+++ b/android/jni/com/mapswithme/util/HttpClient.cpp
@@ -191,12 +191,13 @@ bool HttpClient::RunHttpRequest()
   static jfieldID const dataField = env->GetFieldID(g_httpParamsClazz, "data", "[B");
   if (!m_bodyData.empty())
   {
-    jni::ScopedLocalRef<jbyteArray> const jniPostData(env.get(),
-                                                      env->NewByteArray(m_bodyData.size()));
+    jni::ScopedLocalRef<jbyteArray> const jniPostData(
+        env.get(), env->NewByteArray(static_cast<jsize>(m_bodyData.size())));
+
     if (jni::HandleJavaException(env.get()))
       return false;
 
-    env->SetByteArrayRegion(jniPostData.get(), 0, m_bodyData.size(),
+    env->SetByteArrayRegion(jniPostData.get(), 0, static_cast<jsize>(m_bodyData.size()),
                             reinterpret_cast<const jbyte *>(m_bodyData.data()));
     if (jni::HandleJavaException(env.get()))
       return false;
diff --git a/local_ads/campaign_serialization.cpp b/local_ads/campaign_serialization.cpp
index caac428a6a..7c771af46a 100644
--- a/local_ads/campaign_serialization.cpp
+++ b/local_ads/campaign_serialization.cpp
@@ -72,7 +72,7 @@ std::vector<Campaign> DeserializeV1(std::vector<uint8_t> const & bytes)
   ReaderSource<MemReaderWithExceptions> src({bytes.data(), bytes.size()});
 
   CHECK_EQUAL(ReadPrimitiveFromSource<Version>(src), Version::V1, ());
-  auto const chunksNumber = ReadPrimitiveFromSource<uint64_t>(src);
+  size_t const chunksNumber = static_cast<size_t>(ReadPrimitiveFromSource<uint64_t>(src));
 
   auto const featureIds = ReadVarUintArray<uint32_t>(src, chunksNumber);
   auto const icons = ReadVarUintArray<uint16_t>(src, chunksNumber);
@@ -142,7 +142,7 @@ std::vector<Campaign> DeserializeV2(std::vector<uint8_t> const & bytes)
   ReaderSource<MemReaderWithExceptions> src({bytes.data(), bytes.size()});
 
   CHECK_EQUAL(ReadPrimitiveFromSource<Version>(src), Version::V2, ());
-  auto const chunksNumber = ReadPrimitiveFromSource<uint64_t>(src);
+  size_t const chunksNumber = static_cast<size_t>(ReadPrimitiveFromSource<uint64_t>(src));
 
   auto const featureIds = ReadVarUintArray<uint32_t>(src, chunksNumber);
   auto const icons = ReadVarUintArray<uint16_t>(src, chunksNumber);
diff --git a/platform/network_policy.hpp b/platform/network_policy.hpp
index 615b7e4663..6dca1fc98e 100644
--- a/platform/network_policy.hpp
+++ b/platform/network_policy.hpp
@@ -2,7 +2,7 @@
 
 #include <functional>
 
-class _JNIEnv;
+struct _JNIEnv;
 class _jobject;
 typedef _JNIEnv JNIEnv;
 typedef _jobject * jobject;