diff --git a/src/main/java/org/codelibs/fess/query/QueryCommand.java b/src/main/java/org/codelibs/fess/query/QueryCommand.java
index a56dcec6c..dd8fd8a95 100644
--- a/src/main/java/org/codelibs/fess/query/QueryCommand.java
+++ b/src/main/java/org/codelibs/fess/query/QueryCommand.java
@@ -23,7 +23,6 @@ import org.apache.lucene.search.Query;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.entity.QueryContext;
 import org.codelibs.fess.mylasta.direction.FessConfig;
-import org.codelibs.fess.query.TermQueryCommand.DefaultQueryBuilderFunction;
 import org.codelibs.fess.util.ComponentUtil;
 import org.dbflute.optional.OptionalThing;
 import org.lastaflute.web.util.LaRequestUtil;
@@ -123,4 +122,8 @@ public abstract class QueryCommand {
         }
         return field;
     }
+
+    protected interface DefaultQueryBuilderFunction {
+        QueryBuilder apply(String field, float boost);
+    }
 }
diff --git a/src/main/java/org/codelibs/fess/query/TermQueryCommand.java b/src/main/java/org/codelibs/fess/query/TermQueryCommand.java
index 171a0c87b..13c284900 100644
--- a/src/main/java/org/codelibs/fess/query/TermQueryCommand.java
+++ b/src/main/java/org/codelibs/fess/query/TermQueryCommand.java
@@ -184,8 +184,4 @@ public class TermQueryCommand extends QueryCommand {
         context.addHighlightedQuery(text);
         return QueryBuilders.prefixQuery(siteField, text).boost(boost);
     }
-
-    interface DefaultQueryBuilderFunction {
-        QueryBuilder apply(String field, float boost);
-    }
 }