diff --git a/src/checkstyle/com/puppycrawl/tools/checkstyle/api/LocalizedMessages.java b/src/checkstyle/com/puppycrawl/tools/checkstyle/api/LocalizedMessages.java
index 468cb4969..d3d1777a4 100644
--- a/src/checkstyle/com/puppycrawl/tools/checkstyle/api/LocalizedMessages.java
+++ b/src/checkstyle/com/puppycrawl/tools/checkstyle/api/LocalizedMessages.java
@@ -62,7 +62,9 @@ public class LocalizedMessages
      **/
     public void add(LocalizedMessage aMsg)
     {
-        mMessages.add(aMsg);
+        if (!mMessages.contains(aMsg)) {
+            mMessages.add(aMsg);
+        }
     }
 
     /** @return the number of messages */
diff --git a/src/tests/com/puppycrawl/tools/checkstyle/checks/SimplifyBooleanExpressionCheckTest.java b/src/tests/com/puppycrawl/tools/checkstyle/checks/SimplifyBooleanExpressionCheckTest.java
index dcb833b5a..efa5dd4e4 100644
--- a/src/tests/com/puppycrawl/tools/checkstyle/checks/SimplifyBooleanExpressionCheckTest.java
+++ b/src/tests/com/puppycrawl/tools/checkstyle/checks/SimplifyBooleanExpressionCheckTest.java
@@ -17,8 +17,6 @@ public class SimplifyBooleanExpressionCheckTest
             "42:36: Expression can be simplified.",
             "43:16: Expression can be simplified.",
             "43:32: Expression can be simplified.",
-            // TODO: Change Check.log to avoid duplicate messages
-            "43:32: Expression can be simplified.",
         };
         verify(checkConfig, getPath("InputSimplifyBoolean.java"), expected);
     }