diff --git a/minui/include/private/resources.h b/minui/include/private/resources.h
index 2a83a10..047ebe2 100644
--- a/minui/include/private/resources.h
+++ b/minui/include/private/resources.h
@@ -82,3 +82,6 @@
   // After initialization, we'll keep the file pointer open before destruction of PngHandler.
   std::unique_ptr<FILE, decltype(&fclose)> png_fp_{ nullptr, fclose };
 };
+
+// Overrides the default resource dir, for testing purpose.
+void res_set_resource_dir(const std::string&);
diff --git a/minui/resources.cpp b/minui/resources.cpp
index 9f67cf8..c018d9b 100644
--- a/minui/resources.cpp
+++ b/minui/resources.cpp
@@ -32,7 +32,6 @@
 #include <string>
 #include <vector>
 
-#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <png.h>
 
@@ -40,6 +39,8 @@
 
 #define SURFACE_DATA_ALIGNMENT 8
 
+static std::string g_resource_dir{ "/res/images" };
+
 static GRSurface* malloc_surface(size_t data_size) {
     size_t size = sizeof(GRSurface) + data_size + SURFACE_DATA_ALIGNMENT;
     unsigned char* temp = static_cast<unsigned char*>(malloc(size));
@@ -51,7 +52,7 @@
 }
 
 PngHandler::PngHandler(const std::string& name) {
-  std::string res_path = android::base::StringPrintf("/res/images/%s.png", name.c_str());
+  std::string res_path = g_resource_dir + "/" + name + ".png";
   png_fp_.reset(fopen(res_path.c_str(), "rbe"));
   // Try to read from |name| if the resource path does not work.
   if (!png_fp_) {
@@ -340,6 +341,10 @@
   return 0;
 }
 
+void res_set_resource_dir(const std::string& dirname) {
+  g_resource_dir = dirname;
+}
+
 // This function tests if a locale string stored in PNG (prefix) matches
 // the locale string provided by the system (locale).
 bool matches_locale(const std::string& prefix, const std::string& locale) {