diff --git a/dev/run-tests.py b/dev/run-tests.py
index 450b68123e1fc..818a0c9f48419 100755
--- a/dev/run-tests.py
+++ b/dev/run-tests.py
@@ -365,8 +365,16 @@ def build_spark_assembly_sbt(hadoop_version):
     print("[info] Building Spark assembly (w/Hive 1.2.1) using SBT with these arguments: ",
           " ".join(profiles_and_goals))
     exec_sbt(profiles_and_goals)
-    # Make sure that Java and Scala API documentation can be generated
-    build_spark_unidoc_sbt(hadoop_version)
+
+    # Note that we skip Unidoc build only if Hadoop 2.6 is explicitly set in this SBT build.
+    # Due to a different dependency resolution in SBT & Unidoc by an unknown reason, the
+    # documentation build fails on a specific machine & environment in Jenkins but it was unable
+    # to reproduce. Please see SPARK-20343. This is a band-aid fix that should be removed in
+    # the future.
+    is_hadoop_version_2_6 = os.environ.get("AMPLAB_JENKINS_BUILD_PROFILE") == "hadoop2.6"
+    if not is_hadoop_version_2_6:
+        # Make sure that Java and Scala API documentation can be generated
+        build_spark_unidoc_sbt(hadoop_version)
 
 
 def build_apache_spark(build_tool, hadoop_version):
diff --git a/pom.xml b/pom.xml
index 14370d92a9080..c1174593c1922 100644
--- a/pom.xml
+++ b/pom.xml
@@ -142,7 +142,6 @@
     <ivy.version>2.4.0</ivy.version>
     <oro.version>2.0.8</oro.version>
     <codahale.metrics.version>3.1.2</codahale.metrics.version>
-    <!-- Keep consistent with Avro vesion in SBT build for SPARK-20343 -->
     <avro.version>1.7.7</avro.version>
     <avro.mapred.classifier>hadoop2</avro.mapred.classifier>
     <jets3t.version>0.9.3</jets3t.version>
diff --git a/project/SparkBuild.scala b/project/SparkBuild.scala
index 77dae289f7758..e52baf51aed1a 100644
--- a/project/SparkBuild.scala
+++ b/project/SparkBuild.scala
@@ -318,8 +318,8 @@ object SparkBuild extends PomBuild {
     enable(MimaBuild.mimaSettings(sparkHome, x))(x)
   }
 
-  /* Generate and pick the spark build info from extra-resources and override a dependency */
-  enable(Core.settings ++ CoreDependencyOverrides.settings)(core)
+  /* Generate and pick the spark build info from extra-resources */
+  enable(Core.settings)(core)
 
   /* Unsafe settings */
   enable(Unsafe.settings)(unsafe)
@@ -443,16 +443,6 @@ object DockerIntegrationTests {
   )
 }
 
-/**
- * Overrides to work around sbt's dependency resolution being different from Maven's in Unidoc.
- *
- * Note that, this is a hack that should be removed in the future. See SPARK-20343
- */
-object CoreDependencyOverrides {
-  lazy val settings = Seq(
-    dependencyOverrides += "org.apache.avro" % "avro" % "1.7.7")
-}
-
 /**
  * Overrides to work around sbt's dependency resolution being different from Maven's.
  */