diff --git a/api/src/main/java/org/apache/cloudstack/api/command/admin/storage/UpdateStoragePoolCmd.java b/api/src/main/java/org/apache/cloudstack/api/command/admin/storage/UpdateStoragePoolCmd.java
index 4b0a6ba00b28..adcb173d9771 100644
--- a/api/src/main/java/org/apache/cloudstack/api/command/admin/storage/UpdateStoragePoolCmd.java
+++ b/api/src/main/java/org/apache/cloudstack/api/command/admin/storage/UpdateStoragePoolCmd.java
@@ -19,20 +19,20 @@
 import java.util.List;
 import java.util.Map;
 
-import org.apache.cloudstack.api.ApiCommandResourceType;
-
 import org.apache.cloudstack.api.APICommand;
+import org.apache.cloudstack.api.ApiArgValidator;
+import org.apache.cloudstack.api.ApiCommandResourceType;
 import org.apache.cloudstack.api.ApiConstants;
 import org.apache.cloudstack.api.ApiErrorCode;
 import org.apache.cloudstack.api.BaseCmd;
 import org.apache.cloudstack.api.Parameter;
 import org.apache.cloudstack.api.ServerApiException;
 import org.apache.cloudstack.api.response.StoragePoolResponse;
+import org.apache.commons.collections.MapUtils;
+import org.apache.commons.lang3.ObjectUtils;
 
 import com.cloud.storage.StoragePool;
 import com.cloud.user.Account;
-import org.apache.commons.collections.MapUtils;
-import org.apache.commons.lang3.ObjectUtils;
 
 @SuppressWarnings("rawtypes")
 @APICommand(name = "updateStoragePool", description = "Updates a storage pool.", responseObject = StoragePoolResponse.class, since = "3.0.0",
@@ -56,7 +56,7 @@ public class UpdateStoragePoolCmd extends BaseCmd {
     @Parameter(name = ApiConstants.CAPACITY_IOPS, type = CommandType.LONG, required = false, description = "IOPS CloudStack can provision from this storage pool")
     private Long capacityIops;
 
-    @Parameter(name = ApiConstants.CAPACITY_BYTES, type = CommandType.LONG, required = false, description = "Bytes CloudStack can provision from this storage pool")
+    @Parameter(name = ApiConstants.CAPACITY_BYTES, type = CommandType.LONG, required = false, description = "Bytes CloudStack can provision from this storage pool",validations={ApiArgValidator.PositiveNumber})
     private Long capacityBytes;
 
     @Parameter(name = ApiConstants.ENABLED, type = CommandType.BOOLEAN, required = false, description = "False to disable the pool for allocation of new volumes, true to" +