diff --git a/src/main/java/org/codelibs/fess/app/web/admin/general/AdminGeneralAction.java b/src/main/java/org/codelibs/fess/app/web/admin/general/AdminGeneralAction.java
index b1133a3bb..c949691a0 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/general/AdminGeneralAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/general/AdminGeneralAction.java
@@ -85,7 +85,7 @@ public class AdminGeneralAction extends FessAdminAction {
         updateProperty(Constants.USE_ACL_AS_ROLE,
                 form.useAclAsRole != null && Constants.ON.equalsIgnoreCase(form.useAclAsRole) ? Constants.TRUE : Constants.FALSE);
         updateProperty(Constants.DAY_FOR_CLEANUP_PROPERTY, form.dayForCleanup.toString());
-        updateProperty(Constants.CRAWLING_THREAD_COUNT_PROPERTY, form.crawlingThreadCount);
+        updateProperty(Constants.CRAWLING_THREAD_COUNT_PROPERTY, form.crawlingThreadCount.toString());
         updateProperty(Constants.SEARCH_LOG_PROPERTY,
                 form.searchLog != null && Constants.ON.equalsIgnoreCase(form.searchLog) ? Constants.TRUE : Constants.FALSE);
         updateProperty(Constants.USER_INFO_PROPERTY, form.userInfo != null && Constants.ON.equalsIgnoreCase(form.userInfo) ? Constants.TRUE
@@ -106,14 +106,14 @@ public class AdminGeneralAction extends FessAdminAction {
         updateProperty(Constants.WEB_API_HOT_SEARCH_WORD_PROPERTY,
                 form.hotSearchWord != null && Constants.ON.equalsIgnoreCase(form.hotSearchWord) ? Constants.TRUE : Constants.FALSE);
         updateProperty(Constants.CSV_FILE_ENCODING_PROPERTY, form.csvFileEncoding);
-        updateProperty(Constants.PURGE_SEARCH_LOG_DAY_PROPERTY, form.purgeSearchLogDay);
-        updateProperty(Constants.PURGE_JOB_LOG_DAY_PROPERTY, form.purgeJobLogDay);
-        updateProperty(Constants.PURGE_USER_INFO_DAY_PROPERTY, form.purgeUserInfoDay);
+        updateProperty(Constants.PURGE_SEARCH_LOG_DAY_PROPERTY, form.purgeSearchLogDay.toString());
+        updateProperty(Constants.PURGE_JOB_LOG_DAY_PROPERTY, form.purgeJobLogDay.toString());
+        updateProperty(Constants.PURGE_USER_INFO_DAY_PROPERTY, form.purgeUserInfoDay.toString());
         updateProperty(Constants.PURGE_BY_BOTS_PROPERTY, form.purgeByBots);
         updateProperty(Constants.NOTIFICATION_TO_PROPERTY, form.notificationTo);
         updateProperty(Constants.SUGGEST_SEARCH_LOG_PROPERTY,
                 form.suggestSearchLog != null && Constants.ON.equalsIgnoreCase(form.suggestSearchLog) ? Constants.TRUE : Constants.FALSE);
-        updateProperty(Constants.PURGE_SUGGEST_SEARCH_LOG_DAY_PROPERTY, form.purgeSuggestSearchLogDay);
+        updateProperty(Constants.PURGE_SUGGEST_SEARCH_LOG_DAY_PROPERTY, form.purgeSuggestSearchLogDay.toString());
         updateProperty(Constants.ELASTICSEARCH_WEB_URL_PROPERTY, form.esHttpUrl);
 
         crawlerProperties.store();
@@ -125,7 +125,7 @@ public class AdminGeneralAction extends FessAdminAction {
         form.diffCrawling = crawlerProperties.getProperty(Constants.DIFF_CRAWLING_PROPERTY, Constants.TRUE);
         form.useAclAsRole = crawlerProperties.getProperty(Constants.USE_ACL_AS_ROLE, Constants.FALSE);
         form.dayForCleanup = getPropertyAsInteger(Constants.DAY_FOR_CLEANUP_PROPERTY, 1);
-        form.crawlingThreadCount = crawlerProperties.getProperty(Constants.CRAWLING_THREAD_COUNT_PROPERTY, "5");
+        form.crawlingThreadCount = Integer.parseInt(crawlerProperties.getProperty(Constants.CRAWLING_THREAD_COUNT_PROPERTY, "5"));
         form.searchLog = crawlerProperties.getProperty(Constants.SEARCH_LOG_PROPERTY, Constants.TRUE);
         form.userInfo = crawlerProperties.getProperty(Constants.USER_INFO_PROPERTY, Constants.TRUE);
         form.userFavorite = crawlerProperties.getProperty(Constants.USER_FAVORITE_PROPERTY, Constants.FALSE);
@@ -139,13 +139,17 @@ public class AdminGeneralAction extends FessAdminAction {
         form.failureCountThreshold = getPropertyAsInteger(Constants.FAILURE_COUNT_THRESHOLD_PROPERTY, Constants.DEFAULT_FAILURE_COUNT);
         form.hotSearchWord = crawlerProperties.getProperty(Constants.WEB_API_HOT_SEARCH_WORD_PROPERTY, Constants.TRUE);
         form.csvFileEncoding = crawlerProperties.getProperty(Constants.CSV_FILE_ENCODING_PROPERTY, Constants.UTF_8);
-        form.purgeSearchLogDay = crawlerProperties.getProperty(Constants.PURGE_SEARCH_LOG_DAY_PROPERTY, Constants.DEFAULT_PURGE_DAY);
-        form.purgeJobLogDay = crawlerProperties.getProperty(Constants.PURGE_JOB_LOG_DAY_PROPERTY, Constants.DEFAULT_PURGE_DAY);
-        form.purgeUserInfoDay = crawlerProperties.getProperty(Constants.PURGE_USER_INFO_DAY_PROPERTY, Constants.DEFAULT_PURGE_DAY);
+        form.purgeSearchLogDay =
+                Integer.parseInt(crawlerProperties.getProperty(Constants.PURGE_SEARCH_LOG_DAY_PROPERTY, Constants.DEFAULT_PURGE_DAY));
+        form.purgeJobLogDay =
+                Integer.parseInt(crawlerProperties.getProperty(Constants.PURGE_JOB_LOG_DAY_PROPERTY, Constants.DEFAULT_PURGE_DAY));
+        form.purgeUserInfoDay =
+                Integer.parseInt(crawlerProperties.getProperty(Constants.PURGE_USER_INFO_DAY_PROPERTY, Constants.DEFAULT_PURGE_DAY));
         form.purgeByBots = crawlerProperties.getProperty(Constants.PURGE_BY_BOTS_PROPERTY, Constants.DEFAULT_PURGE_BY_BOTS);
         form.notificationTo = crawlerProperties.getProperty(Constants.NOTIFICATION_TO_PROPERTY, StringUtil.EMPTY);
         form.suggestSearchLog = crawlerProperties.getProperty(Constants.SUGGEST_SEARCH_LOG_PROPERTY, Constants.TRUE);
-        form.purgeSuggestSearchLogDay = crawlerProperties.getProperty(Constants.PURGE_SUGGEST_SEARCH_LOG_DAY_PROPERTY, "30");
+        form.purgeSuggestSearchLogDay =
+                Integer.parseInt(crawlerProperties.getProperty(Constants.PURGE_SUGGEST_SEARCH_LOG_DAY_PROPERTY, "30"));
         form.esHttpUrl = crawlerProperties.getProperty(Constants.ELASTICSEARCH_WEB_URL_PROPERTY, Constants.ELASTICSEARCH_WEB_URL);
     }
 
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/general/EditForm.java b/src/main/java/org/codelibs/fess/app/web/admin/general/EditForm.java
index ccce61f21..d7f5201c1 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/general/EditForm.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/general/EditForm.java
@@ -42,15 +42,16 @@ public class EditForm implements Serializable {
     public String serverRotation;
 
     @Required
-    @Max(1000)
     @Min(-1)
+    @Max(1000)
     @ValidateTypeFailure
     public Integer dayForCleanup;
 
     @Required
-    @Max(100)
     @Min(0)
-    public String crawlingThreadCount;
+    @Max(100)
+    @ValidateTypeFailure
+    public Integer crawlingThreadCount;
 
     @Size(max = 10)
     public String searchLog;
@@ -80,8 +81,8 @@ public class EditForm implements Serializable {
     public String ignoreFailureType;
 
     @Required
-    @Max(10000)
     @Min(-1)
+    @Max(10000)
     @ValidateTypeFailure
     public Integer failureCountThreshold;
 
@@ -92,17 +93,20 @@ public class EditForm implements Serializable {
     @Size(max = 20)
     public String csvFileEncoding;
 
-    @Max(100000)
     @Min(0)
-    public String purgeSearchLogDay;
+    @Max(100000)
+    @ValidateTypeFailure
+    public Integer purgeSearchLogDay;
 
-    @Max(100000)
     @Min(0)
-    public String purgeJobLogDay;
+    @Max(100000)
+    @ValidateTypeFailure
+    public Integer purgeJobLogDay;
 
-    @Max(100000)
     @Min(0)
-    public String purgeUserInfoDay;
+    @Max(100000)
+    @ValidateTypeFailure
+    public Integer purgeUserInfoDay;
 
     @Size(max = 1000)
     public String purgeByBots;
@@ -113,9 +117,10 @@ public class EditForm implements Serializable {
     @Size(max = 10)
     public String suggestSearchLog;
 
-    @Max(100000)
     @Min(0)
-    public String purgeSuggestSearchLogDay;
+    @Max(100000)
+    @ValidateTypeFailure
+    public Integer purgeSuggestSearchLogDay;
 
     @Size(max = 1000)
     public String esHttpUrl;