diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/IOManager.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/IOManager.java
index 2275d00..c3105ab 100644
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/IOManager.java
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/IOManager.java
@@ -83,6 +83,7 @@
                     throw new HyracksDataException("Error writing to file: " + fHandle.getFileReference().toString());
                 }
                 remaining -= len;
+                offset += len;
                 n += len;
             }
             return n;
@@ -104,6 +105,7 @@
                     return -1;
                 }
                 remaining -= len;
+                offset += len;
                 n += len;
             }
             return n;