diff --git a/dbms/src/Functions/lower.cpp b/dbms/src/Functions/lower.cpp
index 38379fa10cd..4f9dec14602 100644
--- a/dbms/src/Functions/lower.cpp
+++ b/dbms/src/Functions/lower.cpp
@@ -15,7 +15,8 @@ using FunctionLower = FunctionStringToString<LowerUpperImpl<'A', 'Z'>, NameLower
 
 void registerFunctionLower(FunctionFactory & factory)
 {
-    factory.registerFunction<FunctionLower>();
+    factory.registerFunction<FunctionLower>(FunctionFactory::CaseInsensitive);
+    factory.registerAlias("lcase", "lower", FunctionFactory::CaseInsensitive);
 }
 
 }
diff --git a/dbms/src/Functions/upper.cpp b/dbms/src/Functions/upper.cpp
index 9a884ccedd8..35300b61c93 100644
--- a/dbms/src/Functions/upper.cpp
+++ b/dbms/src/Functions/upper.cpp
@@ -15,7 +15,8 @@ using FunctionUpper = FunctionStringToString<LowerUpperImpl<'a', 'z'>, NameUpper
 
 void registerFunctionUpper(FunctionFactory & factory)
 {
-    factory.registerFunction<FunctionUpper>();
+    factory.registerFunction<FunctionUpper>(FunctionFactory::CaseInsensitive);
+    factory.registerAlias("ucase", "upper", FunctionFactory::CaseInsensitive);
 }
 
 }
diff --git a/dbms/tests/queries/0_stateless/00765_sql_compatibility_aliases.reference b/dbms/tests/queries/0_stateless/00765_sql_compatibility_aliases.reference
new file mode 100644
index 00000000000..da7e45c0ca0
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00765_sql_compatibility_aliases.reference
@@ -0,0 +1,4 @@
+foo
+FOO
+foo
+FOO
diff --git a/dbms/tests/queries/0_stateless/00765_sql_compatibility_aliases.sql b/dbms/tests/queries/0_stateless/00765_sql_compatibility_aliases.sql
new file mode 100644
index 00000000000..63ab4eb56d0
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00765_sql_compatibility_aliases.sql
@@ -0,0 +1,6 @@
+SET send_logs_level = 'none';
+
+select lcase('FOO');
+select ucase('foo');
+select LOWER('Foo');
+select UPPER('Foo');