diff --git a/mypages/src/main/java/io/leego/mypages/interceptor/PaginationInterceptor.java b/mypages/src/main/java/io/leego/mypages/interceptor/PaginationInterceptor.java
index b319362..2e93c73 100644
--- a/mypages/src/main/java/io/leego/mypages/interceptor/PaginationInterceptor.java
+++ b/mypages/src/main/java/io/leego/mypages/interceptor/PaginationInterceptor.java
@@ -61,17 +61,9 @@ public class PaginationInterceptor implements Interceptor {
     private final ConcurrentMap<String, PaginationUnrefinedParam> unrefinedParamMap = new ConcurrentHashMap<>(64);
 
     public PaginationInterceptor(PaginationSettings settings) {
-        if (settings == null || (settings.getDialect() == null && settings.getSqlDialect() == null)) {
-            throw new IllegalArgumentException("Dialect is not configured.");
-        }
-        // Whether to obtain values from parameter.
-        settings.setObtainValuesFromFields(
-                (settings.getPageFieldName() != null && settings.getSizeFieldName() != null)
-                        || (settings.getOffsetFieldName() != null && settings.getRowsFieldName() != null));
+        settings.initialize();
         this.settings = settings;
-        this.dialect = settings.getDialect() != null
-                ? settings.getDialect()
-                : settings.getSqlDialect().newDialect();
+        this.dialect = settings.getDialect();
     }
 
     @Override
diff --git a/mypages/src/main/java/io/leego/mypages/interceptor/PaginationSettings.java b/mypages/src/main/java/io/leego/mypages/interceptor/PaginationSettings.java
index 8a4bd3a..7c33ea8 100644
--- a/mypages/src/main/java/io/leego/mypages/interceptor/PaginationSettings.java
+++ b/mypages/src/main/java/io/leego/mypages/interceptor/PaginationSettings.java
@@ -209,6 +209,17 @@ public void setMaxSize(int maxSize) {
         this.maxSize = maxSize;
     }
 
+    public void initialize() {
+        if (this.dialect == null && this.sqlDialect == null) {
+            throw new NullPointerException("Dialect is not configured.");
+        }
+        this.obtainValuesFromFields = (this.pageFieldName != null && this.sizeFieldName != null)
+                || (this.offsetFieldName != null && this.rowsFieldName != null);
+        if (this.dialect == null) {
+            this.dialect = this.sqlDialect.newDialect();
+        }
+    }
+
     public static Builder builder() {
         return new Builder();
     }