diff --git a/dbms/src/AggregateFunctions/QuantileTiming.h b/dbms/src/AggregateFunctions/QuantileTiming.h
index fbf4da725c0..8dde3dd5383 100644
--- a/dbms/src/AggregateFunctions/QuantileTiming.h
+++ b/dbms/src/AggregateFunctions/QuantileTiming.h
@@ -487,7 +487,7 @@ private:
         detail::QuantileTimingLarge * large;
     };
 
-    enum class Kind : UInt8
+    enum class Kind : uint8_t
     {
         Tiny = 1,
         Medium = 2,
diff --git a/dbms/src/Common/CombinedCardinalityEstimator.h b/dbms/src/Common/CombinedCardinalityEstimator.h
index b339ad3d032..51c70d8a395 100644
--- a/dbms/src/Common/CombinedCardinalityEstimator.h
+++ b/dbms/src/Common/CombinedCardinalityEstimator.h
@@ -12,11 +12,11 @@ namespace DB
 namespace details
 {
 
-enum class ContainerType : UInt8 { SMALL = 1, MEDIUM = 2, LARGE = 3 };
+enum class ContainerType : uint8_t { SMALL = 1, MEDIUM = 2, LARGE = 3 };
 
 static inline ContainerType max(const ContainerType & lhs, const ContainerType & rhs)
 {
-    UInt8 res = std::max(static_cast<UInt8>(lhs), static_cast<UInt8>(rhs));
+    uint8_t res = std::max(static_cast<uint8_t>(lhs), static_cast<uint8_t>(rhs));
     return static_cast<ContainerType>(res);
 }
 
diff --git a/dbms/src/Interpreters/ClientInfo.h b/dbms/src/Interpreters/ClientInfo.h
index 8cc77e0e387..492cc299a06 100644
--- a/dbms/src/Interpreters/ClientInfo.h
+++ b/dbms/src/Interpreters/ClientInfo.h
@@ -20,20 +20,20 @@ class ReadBuffer;
 class ClientInfo
 {
 public:
-    enum class Interface : UInt8
+    enum class Interface : uint8_t
     {
         TCP = 1,
         HTTP = 2,
     };
 
-    enum class HTTPMethod : UInt8
+    enum class HTTPMethod : uint8_t
     {
         UNKNOWN = 0,
         GET = 1,
         POST = 2,
     };
 
-    enum class QueryKind : UInt8
+    enum class QueryKind : uint8_t
     {
         NO_QUERY = 0,            /// Uninitialized object.
         INITIAL_QUERY = 1,
diff --git a/dbms/src/Interpreters/QueryLog.h b/dbms/src/Interpreters/QueryLog.h
index 22183dd5811..836b37095e9 100644
--- a/dbms/src/Interpreters/QueryLog.h
+++ b/dbms/src/Interpreters/QueryLog.h
@@ -22,7 +22,7 @@ namespace DB
 /// A struct which will be inserted as row into query_log table
 struct QueryLogElement
 {
-    enum Type : UInt8 // Make it signed for compatibility with DataTypeEnum8
+    enum Type : int8_t // Make it signed for compatibility with DataTypeEnum8
     {
         QUERY_START = 1,
         QUERY_FINISH = 2,
diff --git a/dbms/src/Parsers/ASTSelectQuery.h b/dbms/src/Parsers/ASTSelectQuery.h
index 81203585462..7f2d1f1a5e2 100644
--- a/dbms/src/Parsers/ASTSelectQuery.h
+++ b/dbms/src/Parsers/ASTSelectQuery.h
@@ -15,7 +15,7 @@ struct ASTTablesInSelectQueryElement;
 class ASTSelectQuery : public IAST
 {
 public:
-    enum class Expression : UInt8
+    enum class Expression : uint8_t
     {
         WITH,
         SELECT,