diff --git a/genomix/genomix-hyracks/src/main/java/edu/uci/ics/genomix/data/partition/KmerHashPartitioncomputerFactory.java b/genomix/genomix-hyracks/src/main/java/edu/uci/ics/genomix/data/partition/KmerHashPartitioncomputerFactory.java
index d5c4cdb..68faf59 100644
--- a/genomix/genomix-hyracks/src/main/java/edu/uci/ics/genomix/data/partition/KmerHashPartitioncomputerFactory.java
+++ b/genomix/genomix-hyracks/src/main/java/edu/uci/ics/genomix/data/partition/KmerHashPartitioncomputerFactory.java
@@ -47,7 +47,11 @@
 
 //				long l = getLong(buf.array(), startOffset + fieldOffset
 //						+ slotLength);
-				return hashBytes(buf.array(), startOffset + fieldOffset + slotLength, fieldLength) % nParts;
+				int part = hashBytes(buf.array(), startOffset + fieldOffset + slotLength, fieldLength) % nParts;
+				if (part < 0){
+					part = -part;
+				}
+				return part;
 			}
 		};
 	}