diff --git a/mapreduce/CHANGES.txt b/mapreduce/CHANGES.txt
index 32d6ab5b00d..988c40eda0b 100644
--- a/mapreduce/CHANGES.txt
+++ b/mapreduce/CHANGES.txt
@@ -304,6 +304,9 @@ Trunk (unreleased changes)
     MAPREDUCE-2576. Typo in comment in SimulatorLaunchTaskAction.java.
     (Tim Sell via jghoman)
 
+    MAPREDUCE-2550. Fix bin/mapred to work properly from within a source
+    checkout (Eric Yang via todd)
+
 Release 0.22.0 - Unreleased
 
   INCOMPATIBLE CHANGES
diff --git a/mapreduce/bin/mapred b/mapreduce/bin/mapred
index 099d508b210..4a6dd5be312 100755
--- a/mapreduce/bin/mapred
+++ b/mapreduce/bin/mapred
@@ -19,7 +19,11 @@ bin=`which $0`
 bin=`dirname ${bin}`
 bin=`cd "$bin"; pwd`
 
-. $bin/../libexec/mapred-config.sh
+if [ -e $bin/../libexec/mapred-config.sh ]; then
+  . $bin/../libexec/mapred-config.sh
+else
+  . "$bin/mapred-config.sh"
+fi
 
 function print_usage(){
   echo "Usage: mapred [--config confdir] COMMAND"
diff --git a/mapreduce/bin/mapred-config.sh b/mapreduce/bin/mapred-config.sh
index bcf210ffd45..53c12a8d665 100644
--- a/mapreduce/bin/mapred-config.sh
+++ b/mapreduce/bin/mapred-config.sh
@@ -22,10 +22,14 @@ bin=`which "$0"`
 bin=`dirname "${bin}"`
 bin=`cd "$bin"; pwd`
 
-if [ -d "${bin}" ]; then
-  . "$bin"/../libexec/hadoop-config.sh
-elif [ -e "${HADOOP_PREFIX}"/bin/hadoop-config.sh ]; then
-  . "$HADOOP_MAPRED_PREFIX"/bin/hadoop-config.sh
+if [ -e "$bin/../libexec/hadoop-config.sh" ]; then
+  . "$bin/../libexec/hadoop-config.sh"
+elif [ -e "${HADOOP_COMMON_HOME}/bin/hadoop-config.sh" ]; then
+  . "$HADOOP_COMMON_HOME"/bin/hadoop-config.sh
+elif [ -e "${HADOOP_HOME}/bin/hadoop-config.sh" ]; then
+  . "$HADOOP_HOME"/bin/hadoop-config.sh
+elif [ -e "${HADOOP_MAPRED_HOME}/bin/hadoop-config.sh" ]; then
+  . "$HADOOP_MAPRED_HOME"/bin/hadoop-config.sh
 else
   echo "Hadoop common not found."
   exit
diff --git a/mapreduce/bin/start-mapred.sh b/mapreduce/bin/start-mapred.sh
index f7a6533d18c..d511aacbc2b 100755
--- a/mapreduce/bin/start-mapred.sh
+++ b/mapreduce/bin/start-mapred.sh
@@ -21,7 +21,12 @@
 bin=`dirname "${BASH_SOURCE-$0}"`
 bin=`cd "$bin"; pwd`
 
-. $bin/../libexec/mapred-config.sh
+if [ -e $bin/../libexec/mapred-config.sh ]; then
+  . $bin/../libexec/mapred-config.sh
+else
+  . "$bin/mapred-config.sh"
+fi
+
 
 # start mapred daemons
 # start jobtracker first to minimize connection errors at startup
diff --git a/mapreduce/bin/stop-mapred.sh b/mapreduce/bin/stop-mapred.sh
index 90b326af8b9..471593eb4b7 100755
--- a/mapreduce/bin/stop-mapred.sh
+++ b/mapreduce/bin/stop-mapred.sh
@@ -21,7 +21,11 @@
 bin=`dirname "${BASH_SOURCE-$0}"`
 bin=`cd "$bin"; pwd`
 
-. $bin/../libexec/mapred-config.sh
+if [ -e $bin/../libexec/mapred-config.sh ]; then
+  . $bin/../libexec/mapred-config.sh
+else
+  . "$bin/mapred-config.sh"
+fi
 
 "$HADOOP_PREFIX"/bin/hadoop-daemon.sh --config $HADOOP_CONF_DIR --script "$bin"/mapred stop jobtracker
 "$HADOOP_PREFIX"/bin/hadoop-daemons.sh --config $HADOOP_CONF_DIR --script "$bin"/mapred stop tasktracker