diff --git a/transport/include/hidl/HidlBinderSupport.h b/transport/include/hidl/HidlBinderSupport.h
index 1851870..a596917 100644
--- a/transport/include/hidl/HidlBinderSupport.h
+++ b/transport/include/hidl/HidlBinderSupport.h
@@ -19,6 +19,7 @@
 
 #include <hidl/HidlSupport.h>
 #include <hidl/MQDescriptor.h>
+#include <hidl/Static.h>
 #include <hwbinder/IBinder.h>
 #include <hwbinder/Parcel.h>
 
@@ -280,8 +281,6 @@
 
 // ---------------------- support for casting interfaces
 
-extern std::map<std::string, std::function<sp<IBinder>(void*)>> gBnConstructorMap;
-
 // Construct a smallest possible binder from the given interface.
 // If it is remote, then its remote() will be retrieved.
 // Otherwise, the smallest possible BnChild is found where IChild is a subclass of IType
@@ -303,7 +302,7 @@
             }
         });
         if (myDescriptor.empty()) {
-            // interfaceChain fails || types.size() == 0
+            // interfaceChain fails
             return nullptr;
         }
         auto iter = gBnConstructorMap.find(myDescriptor);
diff --git a/transport/include/hidl/HidlTransportSupport.h b/transport/include/hidl/HidlTransportSupport.h
index f8cae2e..1d22cb7 100644
--- a/transport/include/hidl/HidlTransportSupport.h
+++ b/transport/include/hidl/HidlTransportSupport.h
@@ -17,8 +17,8 @@
 #ifndef ANDROID_HIDL_TRANSPORT_SUPPORT_H
 #define ANDROID_HIDL_TRANSPORT_SUPPORT_H
 
-#include <hidl/HidlSupport.h>
 #include <hidl/HidlBinderSupport.h>
+#include <hidl/HidlSupport.h>
 
 namespace android {
 namespace hardware {
diff --git a/transport/include/hidl/Static.h b/transport/include/hidl/Static.h
index 00db8a7..2a40125 100644
--- a/transport/include/hidl/Static.h
+++ b/transport/include/hidl/Static.h
@@ -17,8 +17,10 @@
 // All static variables go here, to control initialization and
 // destruction order in the library.
 
-#include <utils/threads.h>
+#include <android/hidl/base/1.0/IBase.h>
 #include <android/hidl/manager/1.0/IServiceManager.h>
+#include <hwbinder/IBinder.h>
+#include <utils/threads.h>
 
 namespace android {
 namespace hardware {
@@ -27,5 +29,10 @@
 extern Mutex gDefaultServiceManagerLock;
 extern sp<android::hidl::manager::V1_0::IServiceManager> gDefaultServiceManager;
 
+// For HidlBinderSupport
+// value function receives reinterpret_cast<void *>(static_cast<IFoo *>(foo)),
+// returns sp<IBinder>
+extern std::map<std::string, std::function<sp<IBinder>(void*)>> gBnConstructorMap;
+
 }   // namespace hardware
 }   // namespace android