diff --git a/dbms/src/IO/AIOContextPool.cpp b/dbms/src/IO/AIOContextPool.cpp
index 1251bb651b3..3437f53ff81 100644
--- a/dbms/src/IO/AIOContextPool.cpp
+++ b/dbms/src/IO/AIOContextPool.cpp
@@ -84,13 +84,13 @@ void AIOContextPool::fulfillPromises(const io_event events[], const int num_even
     for (const auto & event : boost::make_iterator_range(events, events + num_events))
     {
         /// get id from event
-        const auto id = event.data;
+        const auto completed_id = event.data;
 
         /// set value via promise and release it
-        const auto it = promises.find(id);
+        const auto it = promises.find(completed_id);
         if (it == std::end(promises))
         {
-            LOG_ERROR(&Poco::Logger::get("AIOcontextPool"), "Found io_event with unknown id " << id);
+            LOG_ERROR(&Poco::Logger::get("AIOcontextPool"), "Found io_event with unknown id " << completed_id);
             continue;
         }
 
@@ -126,7 +126,8 @@ std::future<AIOContextPool::BytesRead> AIOContextPool::post(struct iocb & iocb)
     std::unique_lock<std::mutex> lock{mutex};
 
     /// get current id and increment it by one
-    const auto request_id = id++;
+    const auto request_id = next_id;
+    ++next_id;
 
     /// create a promise and put request in "queue"
     promises.emplace(request_id, std::promise<BytesRead>{});
diff --git a/dbms/src/IO/AIOContextPool.h b/dbms/src/IO/AIOContextPool.h
index 8a2d3e4adbe..64d01a0f45b 100644
--- a/dbms/src/IO/AIOContextPool.h
+++ b/dbms/src/IO/AIOContextPool.h
@@ -26,7 +26,7 @@ class AIOContextPool : public ext::singleton<AIOContextPool>
     using BytesRead = ssize_t;
 
     /// Autoincremental id used to identify completed requests
-    ID id{};
+    ID next_id{};
     mutable std::mutex mutex;
     mutable std::condition_variable have_resources;
     std::map<ID, std::promise<BytesRead>> promises;
diff --git a/dbms/src/IO/ReadBufferAIO.cpp b/dbms/src/IO/ReadBufferAIO.cpp
index 1b06f7e7e27..2bc3dfe7d21 100644
--- a/dbms/src/IO/ReadBufferAIO.cpp
+++ b/dbms/src/IO/ReadBufferAIO.cpp
@@ -191,7 +191,7 @@ off_t ReadBufferAIO::doSeek(off_t off, int whence)
 
 void ReadBufferAIO::synchronousRead()
 {
-    CurrentMetrics::Increment metric_increment{CurrentMetrics::Read};
+    CurrentMetrics::Increment metric_increment_read{CurrentMetrics::Read};
 
     prepare();
     bytes_read = ::pread(fd, buffer_begin, region_aligned_size, region_aligned_begin);
@@ -227,7 +227,7 @@ bool ReadBufferAIO::waitForAIOCompletion()
     if (is_eof || !is_pending_read)
         return false;
 
-    CurrentMetrics::Increment metric_increment{CurrentMetrics::Read};
+    CurrentMetrics::Increment metric_increment_read{CurrentMetrics::Read};
 
     bytes_read = future_bytes_read.get();
     is_pending_read = false;
diff --git a/dbms/src/IO/ZlibInflatingReadBuffer.cpp b/dbms/src/IO/ZlibInflatingReadBuffer.cpp
index 4629da1c6f0..4433b0c9bb4 100644
--- a/dbms/src/IO/ZlibInflatingReadBuffer.cpp
+++ b/dbms/src/IO/ZlibInflatingReadBuffer.cpp
@@ -70,7 +70,7 @@ bool ZlibInflatingReadBuffer::nextImpl()
         }
         else
         {
-            int rc = inflateReset(&zstr);
+            rc = inflateReset(&zstr);
             if (rc != Z_OK)
                 throw Exception(std::string("inflateReset failed: ") + zError(rc), ErrorCodes::ZLIB_INFLATE_FAILED);
             return true;
diff --git a/dbms/src/IO/readFloatText.h b/dbms/src/IO/readFloatText.h
index f3c6c55477b..d91a250ac77 100644
--- a/dbms/src/IO/readFloatText.h
+++ b/dbms/src/IO/readFloatText.h
@@ -372,7 +372,7 @@ ReturnType readFloatTextFastImpl(T & x, ReadBuffer & in)
         auto after_point_num_leading_zeros = after_leading_zeros_count - after_point_count;
 
         readUIntTextUpToNSignificantDigits<significant_digits>(after_point, in);
-        int read_digits = in.count() - after_leading_zeros_count;
+        read_digits = in.count() - after_leading_zeros_count;
         after_point_exponent = (read_digits > significant_digits ? -significant_digits : -read_digits) - after_point_num_leading_zeros;
     }