diff --git a/src/main/java/com/alibaba/druid/pool/vendor/MySqlValidConnectionChecker.java b/src/main/java/com/alibaba/druid/pool/vendor/MySqlValidConnectionChecker.java
index cb90043513..a22e627e4c 100644
--- a/src/main/java/com/alibaba/druid/pool/vendor/MySqlValidConnectionChecker.java
+++ b/src/main/java/com/alibaba/druid/pool/vendor/MySqlValidConnectionChecker.java
@@ -99,7 +99,7 @@ public class MySqlValidConnectionChecker extends ValidConnectionCheckerAdapter i
             }
 
             if (clazz.isAssignableFrom(conn.getClass())) {
-                if (validationQueryTimeout < 0) {
+                if (validationQueryTimeout <= 0) {
                     validationQueryTimeout = DEFAULT_VALIDATION_QUERY_TIMEOUT;
                 }
 
diff --git a/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java b/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java
index da7e93ff31..c3138fa947 100644
--- a/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java
+++ b/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java
@@ -74,7 +74,7 @@ public class OracleValidConnectionChecker extends ValidConnectionCheckerAdapter
             return true;
         }
 
-        int queryTimeout = validationQueryTimeout < 0 ? timeout : validationQueryTimeout;
+        int queryTimeout = validationQueryTimeout <= 0 ? timeout : validationQueryTimeout;
 
         Statement stmt = null;
         ResultSet rs = null;
diff --git a/src/main/java/com/alibaba/druid/pool/vendor/PGValidConnectionChecker.java b/src/main/java/com/alibaba/druid/pool/vendor/PGValidConnectionChecker.java
index df8b9f5cbe..73f00c7577 100644
--- a/src/main/java/com/alibaba/druid/pool/vendor/PGValidConnectionChecker.java
+++ b/src/main/java/com/alibaba/druid/pool/vendor/PGValidConnectionChecker.java
@@ -55,7 +55,7 @@ public class PGValidConnectionChecker extends ValidConnectionCheckerAdapter impl
             conn = ((ConnectionProxy) conn).getRawObject();
         }
 
-        int queryTimeout = validationQueryTimeout < 0 ? defaultQueryTimeout : validationQueryTimeout;
+        int queryTimeout = validationQueryTimeout <= 0 ? defaultQueryTimeout : validationQueryTimeout;
 
         Statement stmt = null;
         ResultSet rs = null;