diff --git a/Source/Core/Core/HW/GCMemcardDirectory.cpp b/Source/Core/Core/HW/GCMemcardDirectory.cpp
index 0ac4199a82..a01f70bad1 100644
--- a/Source/Core/Core/HW/GCMemcardDirectory.cpp
+++ b/Source/Core/Core/HW/GCMemcardDirectory.cpp
@@ -13,7 +13,7 @@
 const int NO_INDEX = -1;
 static const char *MC_HDR = "MC_SYSTEM_AREA";
 
-int GCMemcardDirectory::LoadGCI(std::string fileName, DiscIO::IVolume::ECountry card_region, bool currentGameOnly)
+int GCMemcardDirectory::LoadGCI(const std::string& fileName, DiscIO::IVolume::ECountry card_region, bool currentGameOnly)
 {
 	File::IOFile gcifile(fileName, "rb");
 	if (gcifile)
@@ -131,7 +131,7 @@ int GCMemcardDirectory::LoadGCI(std::string fileName, DiscIO::IVolume::ECountry
 	return NO_INDEX;
 }
 
-GCMemcardDirectory::GCMemcardDirectory(std::string directory, int slot, u16 sizeMb, bool ascii, DiscIO::IVolume::ECountry card_region, int gameId)
+GCMemcardDirectory::GCMemcardDirectory(const std::string& directory, int slot, u16 sizeMb, bool ascii, DiscIO::IVolume::ECountry card_region, int gameId)
 : MemoryCardBase(slot, sizeMb)
 , m_GameId(gameId)
 , m_LastBlock(-1)
@@ -652,7 +652,7 @@ void GCIFile::DoState(PointerWrap &p)
 	p.Do(m_used_blocks);
 }
 
-void MigrateFromMemcardFile(std::string strDirectoryName, int card_index)
+void MigrateFromMemcardFile(const std::string& strDirectoryName, int card_index)
 {
 	File::CreateFullPath(strDirectoryName);
 	std::string ini_memcard =
diff --git a/Source/Core/Core/HW/GCMemcardDirectory.h b/Source/Core/Core/HW/GCMemcardDirectory.h
index 699d70d5cc..3d0425e1b1 100644
--- a/Source/Core/Core/HW/GCMemcardDirectory.h
+++ b/Source/Core/Core/HW/GCMemcardDirectory.h
@@ -9,12 +9,12 @@
 
 // Uncomment this to write the system data of the memorycard from directory to disc
 //#define _WRITE_MC_HEADER 1
-void MigrateFromMemcardFile(std::string strDirectoryName, int card_index);
+void MigrateFromMemcardFile(const std::string& strDirectoryName, int card_index);
 
 class GCMemcardDirectory : public MemoryCardBase, NonCopyable
 {
 public:
-	GCMemcardDirectory(std::string directory, int slot = 0, u16 sizeMb = MemCard2043Mb, bool ascii = true,
+	GCMemcardDirectory(const std::string& directory, int slot = 0, u16 sizeMb = MemCard2043Mb, bool ascii = true,
 		DiscIO::IVolume::ECountry  card_region = DiscIO::IVolume::COUNTRY_EUROPE, int gameId = 0);
 	~GCMemcardDirectory();
 	void FlushToFile();
@@ -26,7 +26,7 @@ public:
 	void DoState(PointerWrap &p) override;
 
 private:
-	int LoadGCI(std::string fileName, DiscIO::IVolume::ECountry card_region, bool currentGameOnly);
+	int LoadGCI(const std::string& fileName, DiscIO::IVolume::ECountry card_region, bool currentGameOnly);
 	inline s32 SaveAreaRW(u32 block, bool writing = false);
 	// s32 DirectoryRead(u32 offset, u32 length, u8* destaddress);
 	s32 DirectoryWrite(u32 destaddress, u32 length, u8 *srcaddress);