diff --git a/src/common.h b/src/common.h
index 61beccc..bf067b1 100644
--- a/src/common.h
+++ b/src/common.h
@@ -58,5 +58,6 @@ static inline bool is_2byte_message(uint8_t c) {
 
 // resource.cpp
 SDL_RWops* open_resource(const char* name, const char* type);
+SDL_RWops* open_file(const char* name);
 
 #endif
diff --git a/src/resource.cpp b/src/resource.cpp
index e93d001..2f763e1 100644
--- a/src/resource.cpp
+++ b/src/resource.cpp
@@ -23,3 +23,16 @@ SDL_RWops* open_resource(const char* name, const char* type) {
 	return SDL_RWFromFile(path, "rb");
 #endif
 }
+
+SDL_RWops* open_file(const char* name) {
+#ifdef __ANDROID__
+	// We cannot use SDL_RWFromFile() because it does not resolve relative
+	// paths using the current directory on Android.
+	FILE *fp = fopen(name, "rb");
+	if (!fp)
+		return NULL;
+	return SDL_RWFromFP(fp, SDL_TRUE);
+#else
+	return SDL_RWFromFile(name, "rb");
+#endif
+}
diff --git a/src/sys/ags.cpp b/src/sys/ags.cpp
index e83dc0b..d29d7e3 100644
--- a/src/sys/ags.cpp
+++ b/src/sys/ags.cpp
@@ -63,14 +63,9 @@ AGS::AGS(NACT* parent, const Config& config) : nact(parent), dirty(false)
 	// フォント
 	TTF_Init();
 	if (!config.font_file.empty()) {
-		// We cannot use SDL_RWFromFile() here because it does not resolve
-		// relative paths using the current directory on Android.
-		FILE *fp = fopen(config.font_file.c_str(), "rb");
-		if (!fp)
-			parent->fatal("Cannot open font file %s", config.font_file.c_str());
-		rw_font = SDL_RWFromFP(fp, SDL_TRUE);
+		rw_font = open_file(config.font_file.c_str());
 		if (!rw_font)
-			parent->fatal("Cannot load font file %s: %s", config.font_file.c_str(), SDL_GetError());
+			parent->fatal("Cannot open font file %s", config.font_file.c_str());
 	} else {
 		rw_font = open_resource(FONT_RESOURCE_NAME, "fonts");
 		if (!rw_font)