diff --git a/runtime/oat_file_assistant.cc b/runtime/oat_file_assistant.cc
index 218c490..57c7d4c 100644
--- a/runtime/oat_file_assistant.cc
+++ b/runtime/oat_file_assistant.cc
@@ -406,7 +406,8 @@
 
   return odex_file->GetCompilerFilter();
 }
-std::string OatFileAssistant::ArtFileName(const OatFile* oat_file) const {
+
+static std::string ArtFileName(const OatFile* oat_file) {
   const std::string oat_file_location = oat_file->GetLocation();
   // Replace extension with .art
   const size_t last_ext = oat_file_location.find_last_of('.');
diff --git a/runtime/oat_file_assistant.h b/runtime/oat_file_assistant.h
index d55e373..88bbaba 100644
--- a/runtime/oat_file_assistant.h
+++ b/runtime/oat_file_assistant.h
@@ -179,7 +179,7 @@
   std::unique_ptr<OatFile> GetBestOatFile();
 
   // Open and returns an image space associated with the oat file.
-  gc::space::ImageSpace* OpenImageSpace(const OatFile* oat_file);
+  static gc::space::ImageSpace* OpenImageSpace(const OatFile* oat_file);
 
   // Loads the dex files in the given oat file for the given dex location.
   // The oat file should be up to date for the given dex location.
@@ -238,9 +238,6 @@
   // |OatFileExists() == true|.
   CompilerFilter::Filter OatFileCompilerFilter();
 
-  // Return image file name. Does not cache since it relies on the oat file.
-  std::string ArtFileName(const OatFile* oat_file) const;
-
   // These methods return the status for a given opened oat file with respect
   // to the dex location.
   OatStatus GivenOatFileStatus(const OatFile& file);