diff --git a/Doc/CHANGELOG.TXT b/Doc/CHANGELOG.TXT
index c8409d9b..78b8bb91 100644
--- a/Doc/CHANGELOG.TXT
+++ b/Doc/CHANGELOG.TXT
@@ -146,6 +146,7 @@ Methods:
 * ship.adjustCargo(commodity,amount)
 * ship.removeCollisionException(ship)
 * ship.hasEquipmentProviding(eq)
+* ship.dumpCargo(amount, preferredtype) second parameter
 * player.ship.equipmentStatus(eqKey,true) second parameter
 * SystemInfo.setInterstellarProperty(g,s1,s2,l,k,v,[m]) 
 
diff --git a/src/Core/Entities/ShipEntity.h b/src/Core/Entities/ShipEntity.h
index 4963b005..9878d925 100644
--- a/src/Core/Entities/ShipEntity.h
+++ b/src/Core/Entities/ShipEntity.h
@@ -1122,7 +1122,7 @@ Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q
 - (BOOL) launchCascadeMine;
 - (ShipEntity *) launchEscapeCapsule;
 - (OOCommodityType) dumpCargo;
-- (ShipEntity *) dumpCargoItem;
+- (ShipEntity *) dumpCargoItem:(OOCommodityType)preferred;
 - (OOCargoType) dumpItem: (ShipEntity*) jetto;
 
 - (void) manageCollisions;
diff --git a/src/Core/Entities/ShipEntity.m b/src/Core/Entities/ShipEntity.m
index 1d89119a..b912c7c9 100644
--- a/src/Core/Entities/ShipEntity.m
+++ b/src/Core/Entities/ShipEntity.m
@@ -12341,7 +12341,7 @@ Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q
 // This is a documented AI method; do not change semantics. (Note: AIs don't have access to the return value.)
 - (OOCommodityType) dumpCargo
 {
-	ShipEntity *jetto = [self dumpCargoItem];
+	ShipEntity *jetto = [self dumpCargoItem:nil];
 	if (jetto != nil)
 	{
 		return [jetto commodityType];
@@ -12353,17 +12353,40 @@ Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q
 }
 
 
-- (ShipEntity *) dumpCargoItem
+- (ShipEntity *) dumpCargoItem:(OOCommodityType)preferred
 {
 	ShipEntity				*jetto = nil;
+	NSUInteger				 i = 0;
 	
 	if (([cargo count] > 0)&&([UNIVERSE getTime] - cargo_dump_time > 0.5))  // space them 0.5s or 10m apart
 	{
-		jetto = [[[cargo objectAtIndex:0] retain] autorelease];
+		if (preferred == nil)
+		{
+			jetto = [[[cargo objectAtIndex:0] retain] autorelease];
+		}
+		else
+		{
+			BOOL found = NO;
+			for (i=0;i<[cargo count];i++)
+			{
+				if ([[[cargo objectAtIndex:i] commodityType] isEqualToString:preferred])
+				{
+					jetto = [[[cargo objectAtIndex:i] retain] autorelease];
+					found = YES;
+					break;
+				}
+			}
+			if (found == NO)
+			{
+				// dump anything
+				jetto = [[[cargo objectAtIndex:0] retain] autorelease];
+				i = 0;
+			}
+		}
 		if (jetto != nil)
 		{
 			[self dumpItem:jetto];	// CLASS_CARGO, STATUS_IN_FLIGHT, AI state GLOBAL
-			[cargo removeObjectAtIndex:0];
+			[cargo removeObjectAtIndex:i];
 			[self broadcastAIMessage:@"CARGO_DUMPED"]; // goes only to 16 nearby ships in range, but that should be enough.
 			unsigned i;
 			// only send script event to powered entities
diff --git a/src/Core/Scripting/OOJSShip.m b/src/Core/Scripting/OOJSShip.m
index 83422a01..6af6ae38 100644
--- a/src/Core/Scripting/OOJSShip.m
+++ b/src/Core/Scripting/OOJSShip.m
@@ -2200,7 +2200,8 @@ static JSBool ShipDumpCargo(JSContext *context, uintN argc, jsval *vp)
 	OOJS_NATIVE_ENTER(context)
 	
 	ShipEntity				*thisEnt = nil;
-	
+	OOCommodityType			pref = nil;
+
 	GET_THIS_SHIP(thisEnt);
 	
 	if (EXPECT_NOT([thisEnt isPlayer] && [(PlayerEntity *)thisEnt isDocked]))
@@ -2208,6 +2209,12 @@ static JSBool ShipDumpCargo(JSContext *context, uintN argc, jsval *vp)
 		OOJSReportWarningForCaller(context, @"PlayerShip", @"dumpCargo", @"Can't dump cargo while docked, ignoring.");
 		OOJS_RETURN_NULL;
 	}
+	
+	if (argc > 1)
+	{
+		pref = OOStringFromJSValue(context, OOJS_ARGV[1]);
+	}
+
 	// NPCs can queue multiple items to dump
 	if (!EXPECT_NOT([thisEnt isPlayer]))
 	{
@@ -2216,7 +2223,7 @@ static JSBool ShipDumpCargo(JSContext *context, uintN argc, jsval *vp)
 		if (argc > 0)  gotCount = JS_ValueToInt32(context, OOJS_ARGV[0], &count);
 		if (EXPECT_NOT(!gotCount || count < 1 || count > 64))
 		{
-			OOJSReportBadArguments(context, @"Ship", @"dumpCargo", MIN(argc, 1U), OOJS_ARGV, nil, @"optional quantity (1 to 64)");
+			OOJSReportBadArguments(context, @"Ship", @"dumpCargo", MIN(argc, 1U), OOJS_ARGV, nil, @"optional quantity (1 to 64), optional preferred commodity");
 			return NO;
 		}
 
@@ -2226,7 +2233,7 @@ static JSBool ShipDumpCargo(JSContext *context, uintN argc, jsval *vp)
 		}
 	}
 
-	OOJS_RETURN_OBJECT([thisEnt dumpCargoItem]);
+	OOJS_RETURN_OBJECT([thisEnt dumpCargoItem:pref]);
 	
 	OOJS_NATIVE_EXIT
 }