diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.fir.kt
new file mode 100644
index 00000000000..2c0109dc50a
--- /dev/null
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.fir.kt
@@ -0,0 +1,35 @@
+// !LANGUAGE: +ProhibitUsingNullableTypeParameterAgainstNotNullAnnotated +TypeEnhancementImprovementsInStrictMode
+// JSPECIFY_STATE: strict
+// MUTE_FOR_PSI_CLASS_FILES_READING
+
+// FILE: NonPlatformTypeParameter.java
+import org.jspecify.annotations.*;
+
+public class NonPlatformTypeParameter<T extends @Nullable Object> {
+    public void foo(T t) {}
+    public <E extends @Nullable Object> void bar(E e) {}
+}
+
+// FILE: Test.java
+public class Test {}
+
+// FILE: main.kt
+fun <T : Test> main(a1: NonPlatformTypeParameter<Any?>, a2: NonPlatformTypeParameter<Test>, x: T): Unit {
+    a1.foo(null)
+    a1.bar<Test?>(null)
+    // jspecify_nullness_mismatch
+    a1.bar<T>(<!NULL_FOR_NONNULL_TYPE!>null<!>)
+    a1.bar<T>(x)
+
+    // jspecify_nullness_mismatch
+    a2.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
+    a2.bar<Test?>(null)
+    // jspecify_nullness_mismatch
+    a2.bar<T>(<!NULL_FOR_NONNULL_TYPE!>null<!>)
+    a2.bar<T>(x)
+}
+
+fun testNullable(a1: NonPlatformTypeParameter<Test>, x: Test?) {
+    // jspecify_nullness_mismatch
+    a1.foo(<!ARGUMENT_TYPE_MISMATCH!>x<!>)
+}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.kt
index 5ce76fd29fe..d18580c6d66 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.kt
@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // !LANGUAGE: +ProhibitUsingNullableTypeParameterAgainstNotNullAnnotated +TypeEnhancementImprovementsInStrictMode
 // JSPECIFY_STATE: strict
 // MUTE_FOR_PSI_CLASS_FILES_READING
@@ -28,4 +27,9 @@ fun <T : Test> main(a1: NonPlatformTypeParameter<Any?>, a2: NonPlatformTypeParam
     // jspecify_nullness_mismatch
     a2.bar<T>(<!NULL_FOR_NONNULL_TYPE!>null<!>)
     a2.bar<T>(x)
-}
\ No newline at end of file
+}
+
+fun testNullable(a1: NonPlatformTypeParameter<Test>, x: Test?) {
+    // jspecify_nullness_mismatch
+    a1.foo(<!TYPE_MISMATCH!>x<!>)
+}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.txt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.txt
index bd16bea0036..48a0b2b6033 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.txt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/NonPlatformTypeParameter.txt
@@ -1,6 +1,7 @@
 package
 
 public fun </*0*/ T : Test> main(/*0*/ a1: NonPlatformTypeParameter<kotlin.Any?>, /*1*/ a2: NonPlatformTypeParameter<Test>, /*2*/ x: T): kotlin.Unit
+public fun testNullable(/*0*/ a1: NonPlatformTypeParameter<Test>, /*1*/ x: Test?): kotlin.Unit
 
 public open class NonPlatformTypeParameter</*0*/ T> {
     public constructor NonPlatformTypeParameter</*0*/ T>()
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.fir.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.fir.kt
index a04df4afb1a..339dbed47c5 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.fir.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.fir.kt
@@ -25,3 +25,7 @@ fun <T : Test> main(a1: NonPlatformTypeParameter<Any?>, a2: NonPlatformTypeParam
     a2.bar<T>(null)
     a2.bar<T>(x)
 }
+
+fun testNullable(a1: NonPlatformTypeParameter<Test>, x: Test?) {
+    a1.foo(x)
+}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.kt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.kt
index 99f321fa9c2..ce3fee96616 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.kt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.kt
@@ -27,4 +27,9 @@ fun <T : Test> main(a1: NonPlatformTypeParameter<Any?>, a2: NonPlatformTypeParam
     // jspecify_nullness_mismatch
     a2.bar<T>(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>null<!>)
     a2.bar<T>(x)
-}
\ No newline at end of file
+}
+
+fun testNullable(a1: NonPlatformTypeParameter<Test>, x: Test?) {
+    // jspecify_nullness_mismatch
+    a1.foo(<!NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS!>x<!>)
+}
diff --git a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.txt b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.txt
index 14795ddfbcc..5ffed19ebd3 100644
--- a/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.txt
+++ b/compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/NonPlatformTypeParameter.txt
@@ -1,6 +1,7 @@
 package
 
 public fun </*0*/ T : Test> main(/*0*/ a1: NonPlatformTypeParameter<kotlin.Any?>, /*1*/ a2: NonPlatformTypeParameter<Test>, /*2*/ x: T): kotlin.Unit
+public fun testNullable(/*0*/ a1: NonPlatformTypeParameter<Test>, /*1*/ x: Test?): kotlin.Unit
 
 public open class NonPlatformTypeParameter</*0*/ T : @org.jspecify.annotations.Nullable kotlin.Any!> {
     public constructor NonPlatformTypeParameter</*0*/ T : @org.jspecify.annotations.Nullable kotlin.Any!>()