diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ProfilingPartitionWriterFactory.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ProfilingPartitionWriterFactory.java
index 1011cf3..ea4dbd6 100644
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ProfilingPartitionWriterFactory.java
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ProfilingPartitionWriterFactory.java
@@ -70,7 +70,7 @@
                 long diff = time - prevTime;
                 prevTime = time;
                 do {
-                    byte b = (byte) (diff & 0xef);
+                    byte b = (byte) (diff & 0x7f);
                     diff >>= 7;
                     if (diff != 0) {
                         b |= 0x80;