diff --git a/include/androidfw/ResourceTypes.h b/include/androidfw/ResourceTypes.h
index c022818f9780d..05411ea12a546 100644
--- a/include/androidfw/ResourceTypes.h
+++ b/include/androidfw/ResourceTypes.h
@@ -1284,7 +1284,7 @@ public:
     ~ResTable();
 
     status_t add(Asset* asset, const int32_t cookie, bool copyData,
-                 const void* idmap);
+                 const void* idmap = NULL);
     status_t add(const void *data, size_t size);
     status_t add(ResTable* src);
 
@@ -1548,7 +1548,7 @@ public:
     status_t createIdmap(const ResTable& overlay,
             uint32_t targetCrc, uint32_t overlayCrc,
             const char* targetPath, const char* overlayPath,
-            void** outData, uint32_t* outSize) const;
+            void** outData, size_t* outSize) const;
 
     enum {
         IDMAP_HEADER_SIZE_BYTES = 3 * sizeof(uint32_t) + 2 * 256,