diff --git a/core/src/main/java/org/elasticsearch/common/lucene/search/Queries.java b/core/src/main/java/org/elasticsearch/common/lucene/search/Queries.java
index 479ad0a4c35..01184d1cffb 100644
--- a/core/src/main/java/org/elasticsearch/common/lucene/search/Queries.java
+++ b/core/src/main/java/org/elasticsearch/common/lucene/search/Queries.java
@@ -117,6 +117,9 @@ public class Queries {
         if (minimumShouldMatch == null) {
             return query;
         }
+        // Queries with a single word expanded with synonyms 
+        // have their coordination factor disabled (@see org.apache.lucene.util.QueryBuilder#analyzeBoolean()).
+        // minimumShouldMatch should not be applicable in such case.
         if (query.isCoordDisabled()) {
             return query;
         }