diff --git a/helix-core/src/main/java/org/apache/helix/model/InstanceConfig.java b/helix-core/src/main/java/org/apache/helix/model/InstanceConfig.java
index 1b3acd68d6..29f7db4cb0 100644
--- a/helix-core/src/main/java/org/apache/helix/model/InstanceConfig.java
+++ b/helix-core/src/main/java/org/apache/helix/model/InstanceConfig.java
@@ -656,6 +656,17 @@ public InstanceOperation getInstanceOperation() {
           .build();
     }
 
+    // if instance operation id DISABLE, we override it to ENABLE if instance is enabled
+    if (activeInstanceOperation.equals(InstanceConstants.InstanceOperation.DISABLE)) {
+      // it is not likely that instanceEnabled is unset, because when we set operation to disable,
+      // we always set instanceEnabled to false
+      // If instance is enabled by old version helix (not having instance operation), the instance config
+      // will have HELIX_ENABLED set to true. In this case, we should override the instance operation to ENABLE
+      if ("true".equals(_record.getSimpleField(InstanceConfigProperty.HELIX_ENABLED.name()))) {
+        return new InstanceOperation.Builder().setOperation(InstanceConstants.InstanceOperation.ENABLE).build();
+      }
+    }
+
     return activeInstanceOperation;
   }