diff --git a/pregelix-dataflow-std/pom.xml b/pregelix-dataflow-std/pom.xml
index db10aef..b27d88d 100644
--- a/pregelix-dataflow-std/pom.xml
+++ b/pregelix-dataflow-std/pom.xml
@@ -1,14 +1,15 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>pregelix-dataflow-std</artifactId>
 	<packaging>jar</packaging>
 	<name>pregelix-dataflow-std</name>
 
 	<parent>
-    		<groupId>edu.uci.ics.hyracks</groupId>
-    		<artifactId>pregelix</artifactId>
-    		<version>0.2.3-SNAPSHOT</version>
-  	</parent>
+		<groupId>edu.uci.ics.hyracks</groupId>
+		<artifactId>pregelix</artifactId>
+		<version>0.2.3-SNAPSHOT</version>
+	</parent>
 
 
 	<properties>
@@ -102,11 +103,13 @@
 			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-data-std</artifactId>
 			<version>0.2.3-SNAPSHOT</version>
+			<type>jar</type>
+			<scope>compile</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.apache.hadoop</groupId>
-			<artifactId>hadoop-core</artifactId>
-			<version>0.20.2</version>
+			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hyracks-hdfs-core</artifactId>
+			<version>0.2.3-SNAPSHOT</version>
 			<type>jar</type>
 			<scope>compile</scope>
 		</dependency>
diff --git a/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/FunctionCallOperatorDescriptor.java b/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/FunctionCallOperatorDescriptor.java
index ee3ac82..4cbd6c4 100644
--- a/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/FunctionCallOperatorDescriptor.java
+++ b/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/std/FunctionCallOperatorDescriptor.java
@@ -61,22 +61,21 @@
             private FrameDeserializer frameDeserializer;
             private final IFrameWriter[] writers = new IFrameWriter[outputArity];
             private final IFunction function = functionFactory.createFunction();
+            private ClassLoader ctxCL = Thread.currentThread().getContextClassLoader();
 
             @Override
-            public void close() throws HyracksDataException {
-                if (postHookFactory != null)
-                    postHookFactory.createRuntimeHook().configure(ctx);
-                function.close();
+            public void open() throws HyracksDataException {
+                rd0 = inputRdFactory == null ? recordDescProvider.getInputRecordDescriptor(getActivityId(), 0)
+                        : inputRdFactory.createRecordDescriptor();
+                frameDeserializer = new FrameDeserializer(ctx.getFrameSize(), rd0);
+                ctxCL = Thread.currentThread().getContextClassLoader();
+                Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
                 for (IFrameWriter writer : writers) {
-                    writer.close();
+                    writer.open();
                 }
-            }
-
-            @Override
-            public void fail() throws HyracksDataException {
-                for (IFrameWriter writer : writers) {
-                    writer.fail();
-                }
+                if (preHookFactory != null)
+                    preHookFactory.createRuntimeHook().configure(ctx);
+                function.open(ctx, rd0, writers);
             }
 
             @Override
@@ -89,17 +88,21 @@
             }
 
             @Override
-            public void open() throws HyracksDataException {
-                rd0 = inputRdFactory == null ? recordDescProvider.getInputRecordDescriptor(getActivityId(), 0)
-                        : inputRdFactory.createRecordDescriptor();
-                frameDeserializer = new FrameDeserializer(ctx.getFrameSize(), rd0);
-                Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
+            public void close() throws HyracksDataException {
+                if (postHookFactory != null)
+                    postHookFactory.createRuntimeHook().configure(ctx);
+                function.close();
                 for (IFrameWriter writer : writers) {
-                    writer.open();
+                    writer.close();
                 }
-                if (preHookFactory != null)
-                    preHookFactory.createRuntimeHook().configure(ctx);
-                function.open(ctx, rd0, writers);
+                Thread.currentThread().setContextClassLoader(ctxCL);
+            }
+
+            @Override
+            public void fail() throws HyracksDataException {
+                for (IFrameWriter writer : writers) {
+                    writer.fail();
+                }
             }
 
             @Override
diff --git a/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/FunctionProxy.java b/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/FunctionProxy.java
index 82ac18e..99bca1a 100644
--- a/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/FunctionProxy.java
+++ b/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/FunctionProxy.java
@@ -37,6 +37,7 @@
     private final IFrameWriter[] writers;
     private TupleDeserializer tupleDe;
     private RecordDescriptor inputRd;
+    private ClassLoader ctxCL;
 
     public FunctionProxy(IHyracksTaskContext ctx, IUpdateFunctionFactory functionFactory,
             IRuntimeHookFactory preHookFactory, IRuntimeHookFactory postHookFactory,
@@ -57,6 +58,7 @@
     public void functionOpen() throws HyracksDataException {
         inputRd = inputRdFactory.createRecordDescriptor();
         tupleDe = new TupleDeserializer(inputRd);
+        ctxCL = Thread.currentThread().getContextClassLoader();
         Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
         for (IFrameWriter writer : writers) {
             writer.open();
@@ -124,5 +126,6 @@
         for (IFrameWriter writer : writers) {
             writer.close();
         }
+        Thread.currentThread().setContextClassLoader(ctxCL);
     }
 }