diff --git a/BizHawk.Emulation.Cores/Consoles/Sony/PSX/Octoshock.cs b/BizHawk.Emulation.Cores/Consoles/Sony/PSX/Octoshock.cs
index 64cdfca665..c8c738ac72 100644
--- a/BizHawk.Emulation.Cores/Consoles/Sony/PSX/Octoshock.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Sony/PSX/Octoshock.cs
@@ -201,10 +201,14 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 
 				//todo - cache reader
 				DiscSystem.DiscSectorReader dsr = new DiscSystem.DiscSectorReader(Disc);
-				dsr.ReadLBA_2448(lba, SectorBuffer, 0);
-				Marshal.Copy(SectorBuffer, 0, new IntPtr(dst), 2448);
-
-				return OctoshockDll.SHOCK_OK;
+				int readed = dsr.ReadLBA_2448(lba, SectorBuffer, 0);
+				if (readed == 2448)
+				{
+					Marshal.Copy(SectorBuffer, 0, new IntPtr(dst), 2448);
+					return OctoshockDll.SHOCK_OK;
+				}
+				else
+					return OctoshockDll.SHOCK_ERROR;
 			}
 		}
 
diff --git a/BizHawk.Emulation.DiscSystem/DiscSectorReader.cs b/BizHawk.Emulation.DiscSystem/DiscSectorReader.cs
index 5917fae582..71dd18298e 100644
--- a/BizHawk.Emulation.DiscSystem/DiscSectorReader.cs
+++ b/BizHawk.Emulation.DiscSystem/DiscSectorReader.cs
@@ -87,6 +87,8 @@ namespace BizHawk.Emulation.DiscSystem
 		{
 			var sector = disc.SynthProvider.Get(lba);
 
+			if (sector == null) return 0;
+
 			PrepareBuffer(buffer, offset, 2352);
 			PrepareJob(lba);
 			job.DestBuffer2448 = buf2442;
@@ -110,6 +112,8 @@ namespace BizHawk.Emulation.DiscSystem
 		public int ReadLBA_2448(int lba, byte[] buffer, int offset)
 		{
 			var sector = disc.SynthProvider.Get(lba);
+			
+			if (sector == null) return 0;
 
 			PrepareBuffer(buffer, offset, 2352);
 			PrepareJob(lba);
@@ -122,7 +126,7 @@ namespace BizHawk.Emulation.DiscSystem
 			sector.Synth(job);
 
 			//we went straight to the caller's buffer, so no need to copy
-			return 2442;
+			return 2448;
 		}
 
 		int ReadLBA_2048_Mode1(int lba, byte[] buffer, int offset)
@@ -130,6 +134,8 @@ namespace BizHawk.Emulation.DiscSystem
 			//we can read the 2048 bytes directly
 			var sector = disc.SynthProvider.Get(lba);
 
+			if (sector == null) return 0;
+
 			PrepareBuffer(buffer, offset, 2048);
 			PrepareJob(lba);
 			job.DestBuffer2448 = buf2442;
@@ -147,6 +153,8 @@ namespace BizHawk.Emulation.DiscSystem
 			//we can read the 2048 bytes directly but we have to get them from the mode 2 data
 			var sector = disc.SynthProvider.Get(lba);
 
+			if (sector == null) return 0;
+
 			PrepareBuffer(buffer, offset, 2048);
 			PrepareJob(lba);
 			job.DestBuffer2448 = buf2442;
@@ -167,6 +175,8 @@ namespace BizHawk.Emulation.DiscSystem
 		{
 			var sector = disc.SynthProvider.Get(lba);
 
+			if (sector == null) return 0;
+
 			PrepareBuffer(buffer, offset, 12);
 			PrepareJob(lba);
 			job.DestBuffer2448 = buf2442;
@@ -198,6 +208,8 @@ namespace BizHawk.Emulation.DiscSystem
 				//in no case do we need the ECC so build special flags here
 				var sector = disc.SynthProvider.Get(lba);
 
+				if (sector == null) return 0;
+
 				PrepareBuffer(buffer, offset, 2048);
 				PrepareJob(lba);
 				job.DestBuffer2448 = buf2442;
@@ -273,6 +285,8 @@ namespace BizHawk.Emulation.DiscSystem
 		{
 			var sector = disc.SynthProvider.Get(lba);
 
+			if (sector == null) return 0;
+
 			PrepareJob(lba);
 			job.DestBuffer2448 = buf2442;
 			job.DestOffset = 0;
diff --git a/BizHawk.Emulation.DiscSystem/Internal/SectorSynth.cs b/BizHawk.Emulation.DiscSystem/Internal/SectorSynth.cs
index a16dee9813..07caf7d171 100644
--- a/BizHawk.Emulation.DiscSystem/Internal/SectorSynth.cs
+++ b/BizHawk.Emulation.DiscSystem/Internal/SectorSynth.cs
@@ -133,6 +133,8 @@ namespace BizHawk.Emulation.DiscSystem
 		public ISectorSynthJob2448 Get(int lba)
 		{
 			int index = lba - FirstLBA;
+			if (index < 0) return null;
+			if (index >= Sectors.Count) return null;
 			return Sectors[index];
 		}
 	}
diff --git a/output/dll/octoshock.dll b/output/dll/octoshock.dll
index 1786a3712b..e8a0a325dc 100644
Binary files a/output/dll/octoshock.dll and b/output/dll/octoshock.dll differ
diff --git a/psx/octoshock/psx/psx.cpp b/psx/octoshock/psx/psx.cpp
index bbe63bba12..7a30774eb9 100644
--- a/psx/octoshock/psx/psx.cpp
+++ b/psx/octoshock/psx/psx.cpp
@@ -2415,11 +2415,12 @@ Breakout:
 bool ShockDiscRef::ReadLBA_PW(uint8* pwbuf96, int32 lba, bool hint_fullread)
 {
 	//TODO - whats that hint mean
-	//TODO - should return false if out of range totally
 	//reference:  static const int32 LBA_Read_Minimum = -150;
  //reference:  static const int32 LBA_Read_Maximum = 449849;	// 100 * 75 * 60 - 150 - 1
 	u8 tmp[2448];
-	ReadLBA2448(lba,tmp);
+	s32 ret = ReadLBA2448(lba,tmp);
+	if(ret != SHOCK_OK)
+		return false;
 	memcpy(pwbuf96,tmp+2352,96);
 	return true;
 }