diff --git a/dbms/src/Functions/FunctionsNull.cpp b/dbms/src/Functions/FunctionsNull.cpp
index af2831db383..979c92823ff 100644
--- a/dbms/src/Functions/FunctionsNull.cpp
+++ b/dbms/src/Functions/FunctionsNull.cpp
@@ -19,9 +19,9 @@ void registerFunctionsNull(FunctionFactory & factory)
 {
     factory.registerFunction<FunctionIsNull>();
     factory.registerFunction<FunctionIsNotNull>();
-    factory.registerFunction<FunctionCoalesce>();
-    factory.registerFunction<FunctionIfNull>();
-    factory.registerFunction<FunctionNullIf>();
+    factory.registerFunction<FunctionCoalesce>(FunctionFactory::CaseInsensitive);
+    factory.registerFunction<FunctionIfNull>(FunctionFactory::CaseInsensitive);
+    factory.registerFunction<FunctionNullIf>(FunctionFactory::CaseInsensitive);
     factory.registerFunction<FunctionAssumeNotNull>();
     factory.registerFunction<FunctionToNullable>();
 }
diff --git a/dbms/tests/queries/0_stateless/00433_ifnull.reference b/dbms/tests/queries/0_stateless/00433_ifnull.reference
index c1a59dec60e..4cf982b2116 100644
--- a/dbms/tests/queries/0_stateless/00433_ifnull.reference
+++ b/dbms/tests/queries/0_stateless/00433_ifnull.reference
@@ -28,3 +28,8 @@ x	Nullable(String)
 1	UInt8
 1	UInt8
 \N	Nullable(Nothing)
+0	Nullable(String)
+-1	Nullable(String)
+2	Nullable(String)
+3	Nullable(String)
+4	Nullable(String)
diff --git a/dbms/tests/queries/0_stateless/00433_ifnull.sql b/dbms/tests/queries/0_stateless/00433_ifnull.sql
index cad3eeba534..9071305a87a 100644
--- a/dbms/tests/queries/0_stateless/00433_ifnull.sql
+++ b/dbms/tests/queries/0_stateless/00433_ifnull.sql
@@ -17,3 +17,5 @@ SELECT ifNull(nullIf(toString(number), '1'), nullIf(toString(-number), '-3')) AS
 SELECT ifNull(NULL, 1) AS res, toTypeName(res);
 SELECT ifNull(1, NULL) AS res, toTypeName(res);
 SELECT ifNull(NULL, NULL) AS res, toTypeName(res);
+
+SELECT IFNULL(NULLIF(toString(number), '1'), NULLIF(toString(-number), '-3')) AS res, toTypeName(res) FROM system.numbers LIMIT 5;
diff --git a/dbms/tests/queries/0_stateless/00435_coalesce.reference b/dbms/tests/queries/0_stateless/00435_coalesce.reference
index 20b8288b09c..b236c89c865 100644
--- a/dbms/tests/queries/0_stateless/00435_coalesce.reference
+++ b/dbms/tests/queries/0_stateless/00435_coalesce.reference
@@ -1,4 +1,5 @@
 \N	\N	\N	1	1	1	1
+\N	\N	1
 0	Nullable(UInt64)
 \N	Nullable(UInt64)
 2	Nullable(UInt64)
diff --git a/dbms/tests/queries/0_stateless/00435_coalesce.sql b/dbms/tests/queries/0_stateless/00435_coalesce.sql
index 7c1c519bcb2..3744f5ff290 100644
--- a/dbms/tests/queries/0_stateless/00435_coalesce.sql
+++ b/dbms/tests/queries/0_stateless/00435_coalesce.sql
@@ -1,6 +1,8 @@
 SELECT coalesce(), coalesce(NULL), coalesce(NULL, NULL),
     coalesce(1), coalesce(1, NULL), coalesce(NULL, 1), coalesce(NULL, 1, NULL);
 
+SELECT COALESCE(), COALESCE(NULL), COALESCE(1, NULL);
+
 SELECT coalesce(number % 2 = 0 ? number : NULL, number % 3 = 0 ? number : NULL, number % 5 = 0 ? number : NULL) AS res, toTypeName(res) FROM system.numbers LIMIT 15;
 SELECT coalesce(number % 2 = 0 ? number : NULL, number % 3 = 0 ? number : NULL, number) AS res, toTypeName(res) FROM system.numbers LIMIT 15;
 SELECT coalesce(number % 2 = 0 ? number : NULL, number % 3 = 0 ? number : NULL, 100) AS res, toTypeName(res) FROM system.numbers LIMIT 15;