diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index a6f54e428b1..b1514d737b0 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -1667,6 +1667,10 @@ Release 2.8.0 - UNRELEASED
     HADOOP-12771. Fix typo in JvmPauseMonitor#getNumGcWarnThreadholdExceeded.
     (Xiaobing Zhou via xyao)
 
+    HADOOP-12766. The default value of
+    "hadoop.workaround.non.threadsafe.getpwuid" is different between
+    core-default.xml and NativeIO.java (Akira AJISAKA via cmccabe)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/resources/core-default.xml b/hadoop-common-project/hadoop-common/src/main/resources/core-default.xml
index ed3802fa53e..ceae3ededf5 100644
--- a/hadoop-common-project/hadoop-common/src/main/resources/core-default.xml
+++ b/hadoop-common-project/hadoop-common/src/main/resources/core-default.xml
@@ -429,7 +429,7 @@ for ldap providers in the same way as above does.
 
 <property>
   <name>hadoop.workaround.non.threadsafe.getpwuid</name>
-  <value>false</value>
+  <value>true</value>
   <description>Some operating systems or authentication modules are known to
   have broken implementations of getpwuid_r and getpwgid_r, such that these
   calls are not thread-safe. Symptoms of this problem include JVM crashes