diff --git a/runtime/native/dalvik_system_VMDebug.cc b/runtime/native/dalvik_system_VMDebug.cc
index 6da34bc..fc94266 100644
--- a/runtime/native/dalvik_system_VMDebug.cc
+++ b/runtime/native/dalvik_system_VMDebug.cc
@@ -442,7 +442,7 @@
   kNumRuntimeStats,
 };
 
-static jobject VMDebug_getRuntimeStatInternal(JNIEnv* env, jclass, jint statId) {
+static jstring VMDebug_getRuntimeStatInternal(JNIEnv* env, jclass, jint statId) {
   gc::Heap* heap = Runtime::Current()->GetHeap();
   switch (static_cast<VMDebugRuntimeStatId>(statId)) {
     case VMDebugRuntimeStatId::kArtGcGcCount: {
diff --git a/runtime/native/java_lang_Class.cc b/runtime/native/java_lang_Class.cc
index e518553..a4a8a37 100644
--- a/runtime/native/java_lang_Class.cc
+++ b/runtime/native/java_lang_Class.cc
@@ -532,7 +532,7 @@
 }
 
 static jobject Class_getDeclaredMethodInternal(JNIEnv* env, jobject javaThis,
-                                               jobject name, jobjectArray args) {
+                                               jstring name, jobjectArray args) {
   ScopedFastNativeObjectAccess soa(env);
   DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
   DCHECK(!Runtime::Current()->IsActiveTransaction());
diff --git a/runtime/native/java_lang_String.cc b/runtime/native/java_lang_String.cc
index 9295ff7..b5aea7c 100644
--- a/runtime/native/java_lang_String.cc
+++ b/runtime/native/java_lang_String.cc
@@ -37,7 +37,7 @@
   return soa.Decode<mirror::String>(java_this)->CharAt(index);
 }
 
-static jint String_compareTo(JNIEnv* env, jobject java_this, jobject java_rhs) {
+static jint String_compareTo(JNIEnv* env, jobject java_this, jstring java_rhs) {
   ScopedFastNativeObjectAccess soa(env);
   if (UNLIKELY(java_rhs == nullptr)) {
     ThrowNullPointerException("rhs == null");
@@ -48,7 +48,7 @@
   }
 }
 
-static jstring String_concat(JNIEnv* env, jobject java_this, jobject java_string_arg) {
+static jstring String_concat(JNIEnv* env, jobject java_this, jstring java_string_arg) {
   ScopedFastNativeObjectAccess soa(env);
   if (UNLIKELY(java_string_arg == nullptr)) {
     ThrowNullPointerException("string arg == null");
diff --git a/runtime/native/java_lang_System.cc b/runtime/native/java_lang_System.cc
index 553cbea..390f026 100644
--- a/runtime/native/java_lang_System.cc
+++ b/runtime/native/java_lang_System.cc
@@ -182,50 +182,55 @@
   AsPrimitiveArray<T>(dstArray)->Memmove(dstPos, AsPrimitiveArray<T>(srcArray), srcPos, count);
 }
 
-static void System_arraycopyCharUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                          jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyCharUnchecked(JNIEnv* env, jclass, jcharArray javaSrc, jint srcPos,
+                                          jcharArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::CharArray, Primitive::kPrimChar>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyByteUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                          jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyByteUnchecked(JNIEnv* env, jclass, jbyteArray javaSrc, jint srcPos,
+                                          jbyteArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::ByteArray, Primitive::kPrimByte>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyShortUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                           jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyShortUnchecked(JNIEnv* env, jclass, jshortArray javaSrc, jint srcPos,
+                                           jshortArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::ShortArray, Primitive::kPrimShort>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyIntUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                         jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyIntUnchecked(JNIEnv* env, jclass, jintArray javaSrc, jint srcPos,
+                                         jintArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::IntArray, Primitive::kPrimInt>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyLongUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                          jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyLongUnchecked(JNIEnv* env, jclass, jlongArray javaSrc, jint srcPos,
+                                          jlongArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::LongArray, Primitive::kPrimLong>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyFloatUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                           jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyFloatUnchecked(JNIEnv* env, jclass, jfloatArray javaSrc, jint srcPos,
+                                           jfloatArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::FloatArray, Primitive::kPrimFloat>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyDoubleUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                            jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyDoubleUnchecked(JNIEnv* env, jclass, jdoubleArray javaSrc, jint srcPos,
+                                            jdoubleArray javaDst, jint dstPos, jint count) {
   System_arraycopyTUnchecked<mirror::DoubleArray, Primitive::kPrimDouble>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
 
-static void System_arraycopyBooleanUnchecked(JNIEnv* env, jclass, jobject javaSrc, jint srcPos,
-                                             jobject javaDst, jint dstPos, jint count) {
+static void System_arraycopyBooleanUnchecked(JNIEnv* env,
+                                             jclass,
+                                             jbooleanArray javaSrc,
+                                             jint srcPos,
+                                             jbooleanArray javaDst,
+                                             jint dstPos,
+                                             jint count) {
   System_arraycopyTUnchecked<mirror::BooleanArray, Primitive::kPrimBoolean>(env, javaSrc, srcPos,
       javaDst, dstPos, count);
 }
diff --git a/runtime/native/java_lang_reflect_Array.cc b/runtime/native/java_lang_reflect_Array.cc
index 12d4008..d28f741 100644
--- a/runtime/native/java_lang_reflect_Array.cc
+++ b/runtime/native/java_lang_reflect_Array.cc
@@ -31,7 +31,7 @@
 namespace art {
 
 static jobject Array_createMultiArray(
-    JNIEnv* env, jclass, jclass javaElementClass, jobject javaDimArray) {
+    JNIEnv* env, jclass, jclass javaElementClass, jintArray javaDimArray) {
   ScopedFastNativeObjectAccess soa(env);
   DCHECK(javaElementClass != nullptr);
   StackHandleScope<2> hs(soa.Self());
diff --git a/runtime/native/java_lang_reflect_Executable.cc b/runtime/native/java_lang_reflect_Executable.cc
index e37c14b..a5e70af 100644
--- a/runtime/native/java_lang_reflect_Executable.cc
+++ b/runtime/native/java_lang_reflect_Executable.cc
@@ -249,14 +249,14 @@
   return 0;
 }
 
-static jobject Executable_getMethodNameInternal(JNIEnv* env, jobject javaMethod) {
+static jstring Executable_getMethodNameInternal(JNIEnv* env, jobject javaMethod) {
   ScopedFastNativeObjectAccess soa(env);
   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
   method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
-  return soa.AddLocalReference<jobject>(method->GetNameAsString(soa.Self()));
+  return soa.AddLocalReference<jstring>(method->GetNameAsString(soa.Self()));
 }
 
-static jobject Executable_getMethodReturnTypeInternal(JNIEnv* env, jobject javaMethod) {
+static jclass Executable_getMethodReturnTypeInternal(JNIEnv* env, jobject javaMethod) {
   ScopedFastNativeObjectAccess soa(env);
   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
   method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
@@ -266,7 +266,7 @@
     return nullptr;
   }
 
-  return soa.AddLocalReference<jobject>(return_type);
+  return soa.AddLocalReference<jclass>(return_type);
 }
 
 // TODO: Move this to mirror::Class ? Other mirror types that commonly appear
diff --git a/runtime/native/java_lang_reflect_Field.cc b/runtime/native/java_lang_reflect_Field.cc
index f990c04..688ae19 100644
--- a/runtime/native/java_lang_reflect_Field.cc
+++ b/runtime/native/java_lang_reflect_Field.cc
@@ -460,10 +460,10 @@
   return reinterpret_cast<jlong>(field);
 }
 
-static jobject Field_getNameInternal(JNIEnv* env, jobject javaField) {
+static jstring Field_getNameInternal(JNIEnv* env, jobject javaField) {
   ScopedFastNativeObjectAccess soa(env);
   ArtField* field = soa.Decode<mirror::Field>(javaField)->GetArtField();
-  return soa.AddLocalReference<jobject>(
+  return soa.AddLocalReference<jstring>(
       field->GetStringName(soa.Self(), true /* resolve */));
 }
 
diff --git a/runtime/native/java_lang_reflect_Method.cc b/runtime/native/java_lang_reflect_Method.cc
index b604dc0..4355c06 100644
--- a/runtime/native/java_lang_reflect_Method.cc
+++ b/runtime/native/java_lang_reflect_Method.cc
@@ -82,7 +82,7 @@
 }
 
 static jobject Method_invoke(JNIEnv* env, jobject javaMethod, jobject javaReceiver,
-                             jobject javaArgs) {
+                             jobjectArray javaArgs) {
   ScopedFastNativeObjectAccess soa(env);
   return InvokeMethod(soa, javaMethod, javaReceiver, javaArgs);
 }
diff --git a/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc b/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc
index 836637f..fbee7b3 100644
--- a/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc
+++ b/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc
@@ -162,7 +162,7 @@
   return result;
 }
 
-static jint DdmVmInternal_heapInfoNotify(JNIEnv* env, jclass, jint when) {
+static jboolean DdmVmInternal_heapInfoNotify(JNIEnv* env, jclass, jint when) {
   ScopedFastNativeObjectAccess soa(env);
   return Dbg::DdmHandleHpifChunk(static_cast<Dbg::HpifWhen>(when));
 }
diff --git a/runtime/native/sun_misc_Unsafe.cc b/runtime/native/sun_misc_Unsafe.cc
index b2bdeed..1af65a3 100644
--- a/runtime/native/sun_misc_Unsafe.cc
+++ b/runtime/native/sun_misc_Unsafe.cc
@@ -198,14 +198,14 @@
   obj->SetFieldObject<false>(MemberOffset(offset), newValue);
 }
 
-static jint Unsafe_getArrayBaseOffsetForComponentType(JNIEnv* env, jclass, jobject component_class) {
+static jint Unsafe_getArrayBaseOffsetForComponentType(JNIEnv* env, jclass, jclass component_class) {
   ScopedFastNativeObjectAccess soa(env);
   ObjPtr<mirror::Class> component = soa.Decode<mirror::Class>(component_class);
   Primitive::Type primitive_type = component->GetPrimitiveType();
   return mirror::Array::DataOffset(Primitive::ComponentSize(primitive_type)).Int32Value();
 }
 
-static jint Unsafe_getArrayIndexScaleForComponentType(JNIEnv* env, jclass, jobject component_class) {
+static jint Unsafe_getArrayIndexScaleForComponentType(JNIEnv* env, jclass, jclass component_class) {
   ScopedFastNativeObjectAccess soa(env);
   ObjPtr<mirror::Class> component = soa.Decode<mirror::Class>(component_class);
   Primitive::Type primitive_type = component->GetPrimitiveType();