diff --git a/build.sbt b/build.sbt
index d3d30d97..19f35d08 100644
--- a/build.sbt
+++ b/build.sbt
@@ -12,23 +12,29 @@ scalaVersion := "2.10.4"
 
 parallelExecution in Test := false
 
+libraryDependencies ++= Seq(
+  "edu.arizona.sista" % "processors" % "3.0" exclude("ch.qos.logback", "logback-classic"),
+  "edu.arizona.sista" % "processors" % "3.0" classifier "models",
+  "org.slf4j" % "slf4j-api" % "1.7.2",
+  "org.slf4j" % "slf4j-log4j12" % "1.7.2",
+  "org.scalatest" %% "scalatest" % "1.9.1" % "test",
+  "org.apache.commons" % "commons-compress" % "1.7",
+  "commons-io" % "commons-io" % "2.4",
+  "org.scalanlp" % "breeze_2.10" % "0.11.2",
+  "com.github.fommil.netlib" % "all" % "1.1.2" pomOnly(),
+  "edu.berkeley.cs.amplab" % "mlmatrix" % "0.1" from "https://s3-us-west-1.amazonaws.com/amp-ml-matrix/2.10/mlmatrix_2.10-0.1.jar",
+  "com.github.scopt" %% "scopt" % "3.3.0"
+)
+
 {
+  val defaultSparkVersion = "1.3.1"
+  val sparkVersion =
+    scala.util.Properties.envOrElse("SPARK_VERSION", defaultSparkVersion)
   val excludeHadoop = ExclusionRule(organization = "org.apache.hadoop")
   libraryDependencies ++= Seq(
-    "edu.arizona.sista" % "processors" % "3.0" exclude("ch.qos.logback", "logback-classic"),
-    "edu.arizona.sista" % "processors" % "3.0" classifier "models",
-    "org.slf4j" % "slf4j-api" % "1.7.2",
-    "org.slf4j" % "slf4j-log4j12" % "1.7.2",
-    "org.scalatest" %% "scalatest" % "1.9.1" % "test",
-    "org.apache.spark" % "spark-core_2.10" % "1.3.1" excludeAll(excludeHadoop),
-    "org.apache.spark" % "spark-mllib_2.10" % "1.3.1" excludeAll(excludeHadoop),
-    "org.apache.spark" % "spark-sql_2.10" % "1.3.1" excludeAll(excludeHadoop),
-    "org.apache.commons" % "commons-compress" % "1.7",
-    "commons-io" % "commons-io" % "2.4",
-    "org.scalanlp" % "breeze_2.10" % "0.11.2",
-    "com.github.fommil.netlib" % "all" % "1.1.2" pomOnly(),
-    "edu.berkeley.cs.amplab" % "mlmatrix" % "0.1" from "https://s3-us-west-1.amazonaws.com/amp-ml-matrix/2.10/mlmatrix_2.10-0.1.jar",
-    "com.github.scopt" %% "scopt" % "3.3.0"
+    "org.apache.spark" % "spark-core_2.10" % sparkVersion excludeAll(excludeHadoop),
+    "org.apache.spark" % "spark-mllib_2.10" % sparkVersion excludeAll(excludeHadoop),
+    "org.apache.spark" % "spark-sql_2.10" % sparkVersion excludeAll(excludeHadoop)
   )
 }