diff --git a/include/androidfw/AssetManager.h b/include/androidfw/AssetManager.h
index ac479006cb542..a13dd16fc7366 100644
--- a/include/androidfw/AssetManager.h
+++ b/include/androidfw/AssetManager.h
@@ -231,7 +231,7 @@ public:
      * corresponding overlay package.
      */
     bool createIdmap(const char* targetApkPath, const char* overlayApkPath,
-        uint32_t targetCrc, uint32_t overlayCrc, uint32_t** outData, uint32_t* outSize);
+        uint32_t targetCrc, uint32_t overlayCrc, uint32_t** outData, size_t* outSize);
 
 private:
     struct asset_path
diff --git a/libs/androidfw/AssetManager.cpp b/libs/androidfw/AssetManager.cpp
index 05a948dff25aa..5069958ee1d2e 100644
--- a/libs/androidfw/AssetManager.cpp
+++ b/libs/androidfw/AssetManager.cpp
@@ -285,7 +285,7 @@ bool AssetManager::addOverlayPath(const String8& packagePath, int32_t* cookie)
  }
 
 bool AssetManager::createIdmap(const char* targetApkPath, const char* overlayApkPath,
-        uint32_t targetCrc, uint32_t overlayCrc, uint32_t** outData, uint32_t* outSize)
+        uint32_t targetCrc, uint32_t overlayCrc, uint32_t** outData, size_t* outSize)
 {
     AutoMutex _l(mLock);
     const String8 paths[2] = { String8(targetApkPath), String8(overlayApkPath) };