diff --git a/kotlin-native/backend.native/tests/interop/forwardDeclarationsTwoLibs/forwardDeclarationsTwoLibs.kt b/kotlin-native/backend.native/tests/interop/forwardDeclarationsTwoLibs/forwardDeclarationsTwoLibs.kt
index f30119aa429..814e38a1cfb 100644
--- a/kotlin-native/backend.native/tests/interop/forwardDeclarationsTwoLibs/forwardDeclarationsTwoLibs.kt
+++ b/kotlin-native/backend.native/tests/interop/forwardDeclarationsTwoLibs/forwardDeclarationsTwoLibs.kt
@@ -2,12 +2,13 @@
 
 import cForwardDeclarationsTwoLibs1.*
 import cForwardDeclarationsTwoLibs2.*
-
-// Note: there are no practical cases for this type, but it works in K1 so better to have a test for this.
-import cnames.structs.StructUndeclaredUndeclared
+import cnames.structs.StructUndeclaredDeclared
+import cnames.structs.StructDeclaredUndeclared
+import cnames.structs.StructDeclaredDeclared
 
 import kotlin.test.assertEquals
 import kotlinx.cinterop.COpaque
+import kotlinx.cinterop.CPointed
 import kotlinx.cinterop.CStructVar
 import kotlinx.cinterop.ptr
 // The test should also check that these references can't be resolved, but the test infra doesn't support this yet:
@@ -17,15 +18,11 @@ import kotlinx.cinterop.ptr
 // import cForwardDeclarationsTwoLibs2.StructUndeclaredUndeclared
 // import cForwardDeclarationsTwoLibs2.StructDeclaredUndeclared
 // import cForwardDeclarationsTwoLibs2.StructDefinedUndeclared
+// import cnames.structs.StructUndeclaredUndeclared // Supported in K1 though.
 
 fun <T1 : T2, T2> checkSubtype2() {}
-fun <T1 : T2, T2 : T3, T3> checkSubtype3() {}
-fun <T1 : T2, T2 : T3, T3 : T4, T4> checkSubtype4() {}
-fun <T1 : T2, T2 : T3, T3 : T4, T4 : T5, T5> checkSubtype5() {}
-fun <T1 : T2, T2 : T3, T3 : T4, T4 : T5, T5 : T6, T6> checkSubtype6() {}
 
 // Here we rely on frontend reporting conflicting overloads if some of these types turn out to be the same.
-fun checkDifferentTypes(s: StructUndeclaredUndeclared?) = 0
 fun checkDifferentTypes(s: StructUndeclaredDeclared?) = 1
 fun checkDifferentTypes(s: StructUndeclaredDefined?) = 2
 fun checkDifferentTypes(s: StructDeclaredUndeclared?) = 3
@@ -37,85 +34,37 @@ fun checkDifferentTypes(s: cForwardDeclarationsTwoLibs1.StructDefinedDefined?) =
 fun checkDifferentTypes(s: cForwardDeclarationsTwoLibs2.StructDefinedDefined?) = 9
 
 fun main() {
-    // Checking it is the same type:
-    checkSubtype3<StructUndeclaredUndeclared, cnames.structs.StructUndeclaredUndeclared, StructUndeclaredUndeclared>()
-    checkSubtype2<StructUndeclaredUndeclared, COpaque>()
-
-    checkSubtype4<
-            StructUndeclaredDeclared,
-            cnames.structs.StructUndeclaredDeclared,
-            cForwardDeclarationsTwoLibs2.StructUndeclaredDeclared,
-            StructUndeclaredDeclared,
-    >()
     checkSubtype2<StructUndeclaredDeclared, COpaque>()
 
-    checkSubtype4<
-            StructUndeclaredDefined,
-            cnames.structs.StructUndeclaredDefined,
-            cForwardDeclarationsTwoLibs2.StructUndeclaredDefined,
-            StructUndeclaredDefined
-    >()
     checkSubtype2<StructUndeclaredDefined, CStructVar>()
 
-    checkSubtype4<
-            StructDeclaredUndeclared,
-            cnames.structs.StructDeclaredUndeclared,
-            cForwardDeclarationsTwoLibs1.StructDeclaredUndeclared,
-            StructDeclaredUndeclared
-    >()
     checkSubtype2<StructDeclaredUndeclared, COpaque>()
 
-    checkSubtype5<
-            StructDeclaredDeclared,
-            cnames.structs.StructDeclaredDeclared,
-            cForwardDeclarationsTwoLibs1.StructDeclaredDeclared,
-            cForwardDeclarationsTwoLibs2.StructDeclaredDeclared,
-            StructDeclaredDeclared
-    >()
     checkSubtype2<StructDeclaredDeclared, COpaque>()
 
-    checkSubtype5<
-            StructDeclaredDefined,
-            cnames.structs.StructDeclaredDefined,
-            cForwardDeclarationsTwoLibs1.StructDeclaredDefined,
-            cForwardDeclarationsTwoLibs2.StructDeclaredDefined,
-            StructDeclaredDefined
-    >()
+    checkSubtype2<cnames.structs.StructDeclaredDefined, CPointed>()
     checkSubtype2<StructDeclaredDefined, CStructVar>()
 
-    checkSubtype4<
-            StructDefinedUndeclared,
-            cnames.structs.StructDefinedUndeclared,
-            cForwardDeclarationsTwoLibs1.StructDefinedUndeclared,
-            StructDefinedUndeclared
-    >()
     checkSubtype2<StructDefinedUndeclared, CStructVar>()
 
-    checkSubtype5<
-            StructDefinedDeclared,
-            cnames.structs.StructDefinedDeclared,
-            cForwardDeclarationsTwoLibs1.StructDefinedDeclared,
-            cForwardDeclarationsTwoLibs2.StructDefinedDeclared,
-            StructDefinedDeclared
-    >()
+    checkSubtype2<cnames.structs.StructDefinedDeclared, CPointed>()
     checkSubtype2<StructDefinedDeclared, CStructVar>()
 
-    checkSubtype2<cnames.structs.StructDefinedDefined, CStructVar>()
     checkSubtype2<cForwardDeclarationsTwoLibs1.StructDefinedDefined, CStructVar>()
     checkSubtype2<cForwardDeclarationsTwoLibs2.StructDefinedDefined, CStructVar>()
 
-    val undeclaredUndeclared: StructUndeclaredUndeclared? = null
     val undeclaredDeclared: StructUndeclaredDeclared? = null
     val undeclaredDefined: StructUndeclaredDefined? = null
     val declaredUndeclared: StructDeclaredUndeclared? = null
     val declaredDeclared: StructDeclaredDeclared? = null
+    val cnamesDeclaredDefined: cnames.structs.StructDeclaredDefined? = null
     val declaredDefined: StructDeclaredDefined? = null
     val definedUndeclared: StructDefinedUndeclared? = null
+    val cnamesDefinedDeclared: cnames.structs.StructDefinedDeclared? = null
     val definedDeclared: StructDefinedDeclared? = null
     val definedDefined1: cForwardDeclarationsTwoLibs1.StructDefinedDefined? = null
     val definedDefined2: cForwardDeclarationsTwoLibs2.StructDefinedDefined? = null
 
-    assertEquals(0, checkDifferentTypes(undeclaredUndeclared))
     assertEquals(1, checkDifferentTypes(undeclaredDeclared))
     assertEquals(2, checkDifferentTypes(undeclaredDefined))
     assertEquals(3, checkDifferentTypes(declaredUndeclared))
@@ -131,11 +80,11 @@ fun main() {
     assertEquals(-3, use1StructDeclaredUndeclared(declaredUndeclared?.ptr))
     assertEquals(-4, use1StructDeclaredDeclared(declaredDeclared?.ptr))
     assertEquals(4, use2StructDeclaredDeclared(declaredDeclared?.ptr))
-    assertEquals(-5, use1StructDeclaredDefined(declaredDefined?.ptr))
+    assertEquals(-5, use1StructDeclaredDefined(cnamesDeclaredDefined?.ptr))
     assertEquals(5, use2StructDeclaredDefined(declaredDefined?.ptr))
     assertEquals(-6, use1StructDefinedUndeclared(definedUndeclared?.ptr))
     assertEquals(-7, use1StructDefinedDeclared(definedDeclared?.ptr))
-    assertEquals(7, use2StructDefinedDeclared(definedDeclared?.ptr))
+    assertEquals(7, use2StructDefinedDeclared(cnamesDefinedDeclared?.ptr))
     assertEquals(-8, use1StructDefinedDefined(definedDefined1?.ptr))
     assertEquals(8, use2StructDefinedDefined(definedDefined2?.ptr))
 }