diff --git a/core/src/main/scala/org/apache/spark/internal/config/package.scala b/core/src/main/scala/org/apache/spark/internal/config/package.scala
index 9876848f654a..e9a3780f0aaa 100644
--- a/core/src/main/scala/org/apache/spark/internal/config/package.scala
+++ b/core/src/main/scala/org/apache/spark/internal/config/package.scala
@@ -407,7 +407,8 @@ package object config {
     .createWithDefault(1)
 
   private[spark] val EXECUTOR_MEMORY = ConfigBuilder(SparkLauncher.EXECUTOR_MEMORY)
-    .doc("Amount of memory to use per executor process, in MiB unless otherwise specified.")
+    .doc("Amount of memory to use per executor process, in MiB unless otherwise specified, " +
+      "and with minimum value 450m")
     .version("0.7.0")
     .bytesConf(ByteUnit.MiB)
     .createWithDefaultString("1g")
diff --git a/docs/configuration.md b/docs/configuration.md
index dc9ca63d24d9..ff3d0aa4c262 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -282,7 +282,8 @@ of the most common options to set are:
   <td>1g</td>
   <td>
     Amount of memory to use per executor process, in the same format as JVM memory strings with
-    a size unit suffix ("k", "m", "g" or "t") (e.g. <code>512m</code>, <code>2g</code>).
+    a size unit suffix ("k", "m", "g" or "t") (e.g. <code>512m</code>, <code>2g</code>),
+    and with minimum value <code>450m</code>.
   </td>
   <td>0.7.0</td>
 </tr>