diff --git a/src/main/java/com/googlesource/gerrit/plugins/validators/CommitMessageLengthValidation.java b/src/main/java/com/googlesource/gerrit/plugins/validators/CommitMessageLengthValidation.java
index a8f2969..8214223 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/validators/CommitMessageLengthValidation.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/validators/CommitMessageLengthValidation.java
@@ -13,22 +13,48 @@
 // limitations under the License.
 package com.googlesource.gerrit.plugins.validators;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.AbbreviatedObjectId;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.revwalk.RevCommit;
 
 import com.google.gerrit.extensions.annotations.Listen;
+import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.events.CommitReceivedEvent;
 import com.google.gerrit.server.git.validators.CommitValidationException;
 import com.google.gerrit.server.git.validators.CommitValidationListener;
 import com.google.gerrit.server.git.validators.CommitValidationMessage;
+import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
 @Listen
 @Singleton
 public class CommitMessageLengthValidation implements CommitValidationListener {
+  private final static int DEFAULT_MAX_SUBJECT_LENGTH = 65;
+  private final static int DEFAULT_MAX_LINE_LENGTH = 70;
+  private final static String COMMIT_MESSAGE_SECTION = "commitmessage";
+  private final static String MAX_SUBJECT_LENGTH_KEY = "maxSubjectLength";
+  private final static String MAX_LINE_LENGTH_KEY = "maxLineLength";
+
+  private final Config config;
+  private final int maxSubjectLength;
+  private final int maxLineLength;
+
+  @Inject
+  public CommitMessageLengthValidation(@GerritServerConfig Config gerritConfig)
+      throws ConfigInvalidException, IOException {
+    this.config = gerritConfig;
+    this.maxSubjectLength = config.getInt(
+        COMMIT_MESSAGE_SECTION, null,
+        MAX_SUBJECT_LENGTH_KEY, DEFAULT_MAX_SUBJECT_LENGTH);
+    this.maxLineLength = config.getInt(
+        COMMIT_MESSAGE_SECTION, null,
+        MAX_LINE_LENGTH_KEY, DEFAULT_MAX_LINE_LENGTH);
+  }
 
   @Override
   public List<CommitValidationMessage> onCommitReceived(CommitReceivedEvent receiveEvent)
@@ -37,9 +63,10 @@
     final AbbreviatedObjectId id = commit.abbreviate(7);
     List<CommitValidationMessage> messages = new ArrayList<CommitValidationMessage>();
 
-    if (65 < commit.getShortMessage().length()) {
+    if (this.maxSubjectLength < commit.getShortMessage().length()) {
       messages.add(new CommitValidationMessage("(W) " + id.name() //
-         + ": commit subject >65 characters; use shorter first paragraph", false));
+         + ": commit subject >" + this.maxSubjectLength //
+         + " characters; use shorter first paragraph", false));
     }
 
     int longLineCnt = 0, nonEmptyCnt = 0;
@@ -47,14 +74,15 @@
       if (!line.trim().isEmpty()) {
         nonEmptyCnt++;
       }
-      if (70 < line.length()) {
+      if (this.maxLineLength < line.length()) {
         longLineCnt++;
       }
     }
 
     if (0 < longLineCnt && 33 < longLineCnt * 100 / nonEmptyCnt) {
       messages.add(new CommitValidationMessage("(W) " + id.name() //
-          + ": commit message lines >70 characters; manually wrap lines", false));
+          + ": commit message lines >" + this.maxLineLength //
+          + " characters; manually wrap lines", false));
     }
 
     return messages;
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
new file mode 100644
index 0000000..b3f4821
--- /dev/null
+++ b/src/main/resources/Documentation/config.md
@@ -0,0 +1,17 @@
+Commit Message Length Configuration
+===================================
+
+This plugin checks the length of a commit's commit message
+subject and message body, and reports warnings to the git client
+if the lengths are exceeded.
+
+The maximum lengths of the subject and message body are can be
+configured in the standard Gerrit config file `config.gerrit`.
+
+commitmessage.maxSubjectLength
+:	Maximum length of the commit message's subject line.  If
+	not specified, defaults to 65.
+
+commitmessage.maxLineLength
+:	Maximum length of a line in the commit message's body.  If
+	not specified, defaults to 70.