diff --git a/pcsx2/AsyncFileReader.h b/pcsx2/AsyncFileReader.h
index 73f5a5e572..af167682cc 100644
--- a/pcsx2/AsyncFileReader.h
+++ b/pcsx2/AsyncFileReader.h
@@ -75,8 +75,10 @@ class FlatFileReader : public AsyncFileReader
 	io_context_t m_aio_context;
 #endif
 
+	bool shareWrite;
+
 public:
-	FlatFileReader(void);
+	FlatFileReader(bool shareWrite = false);
 	virtual ~FlatFileReader(void);
 
 	virtual bool Open(const wxString& fileName);
diff --git a/pcsx2/CDVD/InputIsoFile.cpp b/pcsx2/CDVD/InputIsoFile.cpp
index 7eb8d50ff5..feab6b7ecd 100644
--- a/pcsx2/CDVD/InputIsoFile.cpp
+++ b/pcsx2/CDVD/InputIsoFile.cpp
@@ -201,7 +201,10 @@ bool InputIsoFile::Open( const wxString& srcfile, bool testOnly )
 	Close();
 	m_filename = srcfile;
 	
-	m_reader = new FlatFileReader();
+	// Allow write sharing of the iso based on the ini settings.
+	// Mostly useful for romhacking, where the disc is frequently
+	// changed and the emulator would block modifications
+	m_reader = new FlatFileReader(EmuConfig.CdvdShareWrite);
 	m_reader->Open(m_filename);
 
 	bool isBlockdump, isCompressed = false;
diff --git a/pcsx2/Config.h b/pcsx2/Config.h
index 4e662db88f..812ac03f28 100644
--- a/pcsx2/Config.h
+++ b/pcsx2/Config.h
@@ -433,6 +433,7 @@ struct Pcsx2Config
 		bool
 			CdvdVerboseReads	:1,		// enables cdvd read activity verbosely dumped to the console
 			CdvdDumpBlocks		:1,		// enables cdvd block dumping
+			CdvdShareWrite		:1,		// allows the iso to be modified while it's loaded
 			EnablePatches		:1,		// enables patch detection and application
 			EnableCheats		:1,		// enables cheat detection and application
 			EnableWideScreenPatches		:1,
diff --git a/pcsx2/Linux/LnxFlatFileReader.cpp b/pcsx2/Linux/LnxFlatFileReader.cpp
index b19fd25863..3c8ba3c7f7 100644
--- a/pcsx2/Linux/LnxFlatFileReader.cpp
+++ b/pcsx2/Linux/LnxFlatFileReader.cpp
@@ -16,7 +16,7 @@
 #include "PrecompiledHeader.h"
 #include "AsyncFileReader.h"
 
-FlatFileReader::FlatFileReader(void)
+FlatFileReader::FlatFileReader(bool shareWrite) : shareWrite(shareWrite)
 {
 	m_blocksize = 2048;
 	m_fd = 0;
diff --git a/pcsx2/Pcsx2Config.cpp b/pcsx2/Pcsx2Config.cpp
index 283255a2c6..7156256ef8 100644
--- a/pcsx2/Pcsx2Config.cpp
+++ b/pcsx2/Pcsx2Config.cpp
@@ -410,6 +410,7 @@ void Pcsx2Config::LoadSave( IniInterface& ini )
 
 	IniBitBool( CdvdVerboseReads );
 	IniBitBool( CdvdDumpBlocks );
+	IniBitBool( CdvdShareWrite );
 	IniBitBool( EnablePatches );
 	IniBitBool( EnableCheats );
 	IniBitBool( EnableWideScreenPatches );
diff --git a/pcsx2/windows/FlatFileReaderWindows.cpp b/pcsx2/windows/FlatFileReaderWindows.cpp
index 64709f5af5..f08cea6d4c 100644
--- a/pcsx2/windows/FlatFileReaderWindows.cpp
+++ b/pcsx2/windows/FlatFileReaderWindows.cpp
@@ -1,22 +1,22 @@
-/*  PCSX2 - PS2 Emulator for PCs
- *  Copyright (C) 2002-2014  PCSX2 Dev Team
- *
- *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
- *  of the GNU Lesser General Public License as published by the Free Software Found-
- *  ation, either version 3 of the License, or (at your option) any later version.
- *
- *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
- *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
- *  PURPOSE.  See the GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License along with PCSX2.
- *  If not, see <http://www.gnu.org/licenses/>.
- */
-
+/*  PCSX2 - PS2 Emulator for PCs
+ *  Copyright (C) 2002-2014  PCSX2 Dev Team
+ *
+ *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU Lesser General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with PCSX2.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include "PrecompiledHeader.h"
 #include "AsyncFileReader.h"
 
-FlatFileReader::FlatFileReader(void)
+FlatFileReader::FlatFileReader(bool shareWrite) : shareWrite(shareWrite)
 {
 	m_blocksize = 2048;
 	hOverlappedFile = INVALID_HANDLE_VALUE;
@@ -35,10 +35,14 @@ bool FlatFileReader::Open(const wxString& fileName)
 
 	hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
 
+	DWORD shareMode = FILE_SHARE_READ;
+	if (shareWrite)
+		shareMode |= FILE_SHARE_WRITE;
+
 	hOverlappedFile = CreateFile(
 		fileName,
 		GENERIC_READ,
-		FILE_SHARE_READ,
+		shareMode,
 		NULL,
 		OPEN_EXISTING,
 		FILE_FLAG_SEQUENTIAL_SCAN | FILE_FLAG_OVERLAPPED,