diff --git a/Core/FileSystems/ISOFileSystem.cpp b/Core/FileSystems/ISOFileSystem.cpp
index fcdc2794aa..b7ab43b11b 100644
--- a/Core/FileSystems/ISOFileSystem.cpp
+++ b/Core/FileSystems/ISOFileSystem.cpp
@@ -299,9 +299,8 @@ void ISOFileSystem::ReadDirectory(u32 startsector, u32 dirsize, TreeEntry *root,
 
 ISOFileSystem::TreeEntry *ISOFileSystem::GetFromPath(std::string path, bool catchError)
 {
-	if (path.length() == 0)
-	{
-		//Ah, the device!	"umd0:"
+	if (path.length() == 0) {
+		// Ah, the device!	"umd0:"
 		return &entireISO;
 	}
 
@@ -311,9 +310,6 @@ ISOFileSystem::TreeEntry *ISOFileSystem::GetFromPath(std::string path, bool catc
 	if (path[0] == '/')
 		path.erase(0,1);
 
-	if (path == "umd0")
-		return &entireISO;
-
 	TreeEntry *e = treeroot;
 	if (path.length() == 0)
 		return e;
@@ -726,6 +722,12 @@ std::string ISOFileSystem::EntryFullPath(TreeEntry *e)
 	return path;
 }
 
+ISOFileSystem::TreeEntry::~TreeEntry() {
+	for (size_t i = 0; i < children.size(); ++i)
+		delete children[i];
+	children.clear();
+}
+
 void ISOFileSystem::DoState(PointerWrap &p)
 {
 	auto s = p.Section("ISOFileSystem", 1);
diff --git a/Core/FileSystems/ISOFileSystem.h b/Core/FileSystems/ISOFileSystem.h
index f124dfdf43..83e2045cda 100644
--- a/Core/FileSystems/ISOFileSystem.h
+++ b/Core/FileSystems/ISOFileSystem.h
@@ -31,35 +31,31 @@ class ISOFileSystem : public IFileSystem
 public:
 	ISOFileSystem(IHandleAllocator *_hAlloc, BlockDevice *_blockDevice, std::string _restrictPath = "");
 	~ISOFileSystem();
-	void DoState(PointerWrap &p);
-	std::vector<PSPFileInfo> GetDirListing(std::string path);
-	u32      OpenFile(std::string filename, FileAccess access, const char *devicename=NULL);
-	void     CloseFile(u32 handle);
-	size_t   ReadFile(u32 handle, u8 *pointer, s64 size);
-	size_t   SeekFile(u32 handle, s32 position, FileMove type);
-	PSPFileInfo GetFileInfo(std::string filename);
-	bool     OwnsHandle(u32 handle);
-	int      Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec);
-	int      DevType(u32 handle);
-	int      Flags() { return 0; }
 
-	size_t WriteFile(u32 handle, const u8 *pointer, s64 size);
+	void DoState(PointerWrap &p) override;
+	std::vector<PSPFileInfo> GetDirListing(std::string path) override;
+	u32      OpenFile(std::string filename, FileAccess access, const char *devicename = NULL) override;
+	void     CloseFile(u32 handle) override;
+	size_t   ReadFile(u32 handle, u8 *pointer, s64 size) override;
+	size_t   SeekFile(u32 handle, s32 position, FileMove type) override;
+	PSPFileInfo GetFileInfo(std::string filename) override;
+	bool     OwnsHandle(u32 handle) override;
+	int      Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec) override;
+	int      DevType(u32 handle) override;
+	int      Flags() override { return 0; }
+
+	size_t WriteFile(u32 handle, const u8 *pointer, s64 size) override;
 	bool GetHostPath(const std::string &inpath, std::string &outpath) {return false;}
-	virtual bool MkDir(const std::string &dirname) {return false;}
-	virtual bool RmDir(const std::string &dirname) {return false;}
-	virtual int  RenameFile(const std::string &from, const std::string &to) {return -1;}
-	virtual bool RemoveFile(const std::string &filename) {return false;}
+	bool MkDir(const std::string &dirname) override {return false;}
+	bool RmDir(const std::string &dirname) override { return false; }
+	int  RenameFile(const std::string &from, const std::string &to) override { return -1; }
+	bool RemoveFile(const std::string &filename) override { return false; }
 
 private:
 	struct TreeEntry
 	{
 		TreeEntry(){}
-		~TreeEntry()
-		{
-			for (size_t i = 0; i < children.size(); ++i)
-				delete children[i];
-			children.clear();
-		}
+		~TreeEntry();
 
 		std::string name;
 		u32 flags;
@@ -81,7 +77,6 @@ private:
 		u32 openSize;
 	};
 	
-
 	typedef std::map<u32,OpenFileEntry> EntryMap;
 	EntryMap entries;
 	IHandleAllocator *hAlloc;
@@ -94,6 +89,55 @@ private:
 	std::vector<std::string> restrictTree;
 
 	void ReadDirectory(u32 startsector, u32 dirsize, TreeEntry *root, size_t level);
-	TreeEntry *GetFromPath(std::string path, bool catchError=true);
+	TreeEntry *GetFromPath(std::string path, bool catchError = true);
 	std::string EntryFullPath(TreeEntry *e);
 };
+
+// On the "umd0:" device, any file you open is the entire ISO.
+// Simply wrap around an ISOFileSystem which has all the necessary machinery, while changing
+// the filenames to "", to achieve this.
+class OnlyEntireISOFileSystem : public IFileSystem {
+public:
+	OnlyEntireISOFileSystem(ISOFileSystem *isoFileSystem) : isoFileSystem_(isoFileSystem) {}
+
+	void DoState(PointerWrap &p) override {}
+
+	std::vector<PSPFileInfo> GetDirListing(std::string path) override { return std::vector<PSPFileInfo>(); }
+	u32      OpenFile(std::string filename, FileAccess access, const char *devicename = NULL) override {
+		return isoFileSystem_->OpenFile("", access, devicename);
+	}
+	void     CloseFile(u32 handle) override {
+		isoFileSystem_->CloseFile(handle);
+	}
+	size_t   ReadFile(u32 handle, u8 *pointer, s64 size) override {
+		return isoFileSystem_->ReadFile(handle, pointer, size);
+	}
+	size_t   SeekFile(u32 handle, s32 position, FileMove type) override {
+		return isoFileSystem_->SeekFile(handle, position, type);
+	}
+	PSPFileInfo GetFileInfo(std::string filename) override {
+		return isoFileSystem_->GetFileInfo("");
+	}
+	bool     OwnsHandle(u32 handle) override {
+		return isoFileSystem_->OwnsHandle(handle);
+	}
+	int      Ioctl(u32 handle, u32 cmd, u32 indataPtr, u32 inlen, u32 outdataPtr, u32 outlen, int &usec) override {
+		return isoFileSystem_->Ioctl(handle, cmd, indataPtr, inlen, outdataPtr, outlen, usec);
+	}
+	int      DevType(u32 handle) override {
+		return isoFileSystem_->DevType(handle);
+	}
+	int      Flags() override { return isoFileSystem_->Flags(); }
+
+	size_t WriteFile(u32 handle, const u8 *pointer, s64 size) override {
+		return isoFileSystem_->WriteFile(handle, pointer, size);
+	}
+	bool GetHostPath(const std::string &inpath, std::string &outpath) { return false; }
+	bool MkDir(const std::string &dirname) override { return false; }
+	bool RmDir(const std::string &dirname) override { return false; }
+	int  RenameFile(const std::string &from, const std::string &to) override { return -1; }
+	bool RemoveFile(const std::string &filename) override { return false; }
+
+private:
+	ISOFileSystem *isoFileSystem_;
+};
\ No newline at end of file
diff --git a/Core/PSPLoaders.cpp b/Core/PSPLoaders.cpp
index 0ccdc591c7..2ab74038dc 100644
--- a/Core/PSPLoaders.cpp
+++ b/Core/PSPLoaders.cpp
@@ -60,6 +60,7 @@ void InitMemoryForGameISO(std::string fileToStart) {
 	FileInfo info;
 	if (!getFileInfo(fileToStart.c_str(), &info)) return;
 
+	bool actualIso = false;
 	if (info.isDirectory)
 	{
 		umd2 = new VirtualDiscFileSystem(&pspFileSystem, fileToStart);
@@ -71,15 +72,24 @@ void InitMemoryForGameISO(std::string fileToStart) {
 		if (!bd)
 			return;
 		umd2 = new ISOFileSystem(&pspFileSystem, bd);
+		actualIso = true;
 	}
 
 	// Parse PARAM.SFO
 
 	//pspFileSystem.Mount("host0:",umd2);
-	pspFileSystem.Mount("umd0:", umd2);
-	pspFileSystem.Mount("umd1:", umd2);
+
+	IFileSystem *entireIso = 0;
+	if (actualIso) {
+		entireIso = new OnlyEntireISOFileSystem(static_cast<ISOFileSystem *>(umd2));
+	} else {
+		entireIso = umd2;
+	}
+
+	pspFileSystem.Mount("umd0:", entireIso);
+	pspFileSystem.Mount("umd1:", entireIso);
 	pspFileSystem.Mount("disc0:", umd2);
-	pspFileSystem.Mount("umd:", umd2);
+	pspFileSystem.Mount("umd:", entireIso);
 
 	std::string gameID;