diff --git a/compiler/fir/resolve/testData/builtIns/kotlin.txt b/compiler/fir/resolve/testData/builtIns/kotlin.txt
index 1a85c03c397..b8b6b095158 100644
--- a/compiler/fir/resolve/testData/builtIns/kotlin.txt
+++ b/compiler/fir/resolve/testData/builtIns/kotlin.txt
@@ -52,7 +52,7 @@ public final class Array<T> : R|kotlin/Any| {
     public final val size: R|kotlin/Int|
         public get(): R|kotlin/Int|
 
-    public constructor<T>(size: R|kotlin/Int|, init: R|kotlin/Function1<kotlin/Int, T>|): R|kotlin/Array<T>|
+    public constructor<T>(size: R|kotlin/Int|, init: R|(kotlin/Int) -> T|): R|kotlin/Array<T>|
 
 }
 
diff --git a/compiler/fir/resolve/testData/loadCompiledKotlin/constructor/vararg/ConstructorNonLastVararg.txt b/compiler/fir/resolve/testData/loadCompiledKotlin/constructor/vararg/ConstructorNonLastVararg.txt
index 9f25c101f1c..f433130c23b 100644
--- a/compiler/fir/resolve/testData/loadCompiledKotlin/constructor/vararg/ConstructorNonLastVararg.txt
+++ b/compiler/fir/resolve/testData/loadCompiledKotlin/constructor/vararg/ConstructorNonLastVararg.txt
@@ -1,4 +1,4 @@
 public final class A : R|kotlin/Any| {
-    public constructor(vararg a: R|kotlin/IntArray|, f: R|kotlin/Function0<kotlin/Unit>|): R|test/A|
+    public constructor(vararg a: R|kotlin/IntArray|, f: R|() -> kotlin/Unit|): R|test/A|
 
 }
diff --git a/compiler/fir/resolve/testData/loadCompiledKotlin/fromLoadJava/kotlinSignature/MethodWithFunctionTypes.txt b/compiler/fir/resolve/testData/loadCompiledKotlin/fromLoadJava/kotlinSignature/MethodWithFunctionTypes.txt
index 91f4fd83246..cf52d359cce 100644
--- a/compiler/fir/resolve/testData/loadCompiledKotlin/fromLoadJava/kotlinSignature/MethodWithFunctionTypes.txt
+++ b/compiler/fir/resolve/testData/loadCompiledKotlin/fromLoadJava/kotlinSignature/MethodWithFunctionTypes.txt
@@ -1,5 +1,5 @@
 public open class MethodWithFunctionTypes : R|kotlin/Any| {
-    public open fun foo(f: R|kotlin/Function1<kotlin/String?, kotlin/String>|): @R|kotlin/ExtensionFunctionType|() R|kotlin/Function1<kotlin/String, kotlin/String?>?|
+    public open fun foo(f: R|(kotlin/String?) -> kotlin/String|): R|kotlin/String.() -> kotlin/String?|
 
     public constructor(): R|test/MethodWithFunctionTypes|
 
diff --git a/compiler/fir/resolve/testData/loadCompiledKotlin/fun/vararg/NonLastVararg.txt b/compiler/fir/resolve/testData/loadCompiledKotlin/fun/vararg/NonLastVararg.txt
index 6fa10b19a3f..f8628b0bdb5 100644
--- a/compiler/fir/resolve/testData/loadCompiledKotlin/fun/vararg/NonLastVararg.txt
+++ b/compiler/fir/resolve/testData/loadCompiledKotlin/fun/vararg/NonLastVararg.txt
@@ -1,3 +1,4 @@
-public final fun f(vararg t: R|kotlin/Array<out kotlin/String>|, f: R|kotlin/Function0<kotlin/Unit>|): R|kotlin/Unit|
+public final fun f(vararg t: R|kotlin/Array<out kotlin/String>|, f: R|() -> kotlin/Unit|): R|kotlin/Unit|
+
+public final fun f(vararg t: R|kotlin/IntArray|, f: R|() -> kotlin/Unit|): R|kotlin/Unit|
 
-public final fun f(vararg t: R|kotlin/IntArray|, f: R|kotlin/Function0<kotlin/Unit>|): R|kotlin/Unit|
diff --git a/compiler/fir/resolve/testData/loadCompiledKotlin/inline/InlineFunction.txt b/compiler/fir/resolve/testData/loadCompiledKotlin/inline/InlineFunction.txt
index e11a4a2fee0..9a7b7f6825a 100644
--- a/compiler/fir/resolve/testData/loadCompiledKotlin/inline/InlineFunction.txt
+++ b/compiler/fir/resolve/testData/loadCompiledKotlin/inline/InlineFunction.txt
@@ -2,6 +2,6 @@ public final inline fun a(): R|kotlin/Unit|
 
 public final inline fun b(): R|kotlin/Unit|
 
-public final inline fun c(crossinline f: R|kotlin/Function0<kotlin/Unit>|): R|kotlin/Unit|
+public final inline fun c(crossinline f: R|() -> kotlin/Unit|): R|kotlin/Unit|
 
 public final inline fun d(): R|kotlin/Unit|
diff --git a/compiler/fir/resolve/testData/loadCompiledKotlin/type/Function1IntString.txt b/compiler/fir/resolve/testData/loadCompiledKotlin/type/Function1IntString.txt
index 8ef93178ea3..6e135a5e9ba 100644
--- a/compiler/fir/resolve/testData/loadCompiledKotlin/type/Function1IntString.txt
+++ b/compiler/fir/resolve/testData/loadCompiledKotlin/type/Function1IntString.txt
@@ -1 +1,2 @@
-public final fun fun1(): R|kotlin/Function1<kotlin/String, kotlin/Int>|
+public final fun fun1(): R|(kotlin/String) -> kotlin/Int|
+
diff --git a/compiler/fir/resolve/testData/loadCompiledKotlin/typealias/TypeAliasToExtension.txt b/compiler/fir/resolve/testData/loadCompiledKotlin/typealias/TypeAliasToExtension.txt
index 5bc662a86d9..339f457d992 100644
--- a/compiler/fir/resolve/testData/loadCompiledKotlin/typealias/TypeAliasToExtension.txt
+++ b/compiler/fir/resolve/testData/loadCompiledKotlin/typealias/TypeAliasToExtension.txt
@@ -1,4 +1,4 @@
-public final fun <P> foo(x: @R|kotlin/ExtensionFunctionType|() R|kotlin/Function1<test/Foo<P>, kotlin/Unit>|): R|kotlin/Unit|
+public final fun <P> foo(x: R|test/Foo<P>.() -> kotlin/Unit|): R|kotlin/Unit|
 
 public final class Foo<T> : R|kotlin/Any| {
     public constructor<T>(): R|test/Foo<T>|