diff --git a/core/src/main/scala/org/apache/spark/SparkContext.scala b/core/src/main/scala/org/apache/spark/SparkContext.scala
index 25f7a5ed1c250f22f033be3bbc2d2178a53cbc8d..5a6d06b66e85bc2a8881cf186ee84493c7b69ab2 100644
--- a/core/src/main/scala/org/apache/spark/SparkContext.scala
+++ b/core/src/main/scala/org/apache/spark/SparkContext.scala
@@ -170,6 +170,11 @@ class SparkContext(
     .map(Utils.memoryStringToMb)
     .getOrElse(512)
 
+  if (!conf.contains("spark.executor.memory") && sys.env.contains("SPARK_MEM")) {
+    logWarning("Using SPARK_MEM to set amount of memory to use per executor process is " +
+      "deprecated, instead use spark.executor.memory")
+  }
+
   // Environment variables to pass to our executors
   private[spark] val executorEnvs = HashMap[String, String]()
   // Note: SPARK_MEM is included for Mesos, but overwritten for standalone mode in ExecutorRunner