diff --git a/certora/specs/ERC20Wrapper.spec b/certora/specs/ERC20Wrapper.spec
index 6e40c61d2..126be7297 100644
--- a/certora/specs/ERC20Wrapper.spec
+++ b/certora/specs/ERC20Wrapper.spec
@@ -12,7 +12,7 @@ methods {
 
 
 // STATUS - verified
-// totalsupply of wrapped should be less than or equal to underlying (assuming no transfer they should be equal) - solvency
+// totalsupply of wrapped should be less than or equal to underlying (assuming no external transfer) - solvency
 invariant whatAboutTotal(env e)
     totalSupply(e) <= underlyingTotalSupply()
     filtered { f -> f.selector != certorafallback_0().selector }
@@ -29,6 +29,18 @@ invariant whatAboutTotal(env e)
     }
 
 
+// STATUS - in progress
+// https://vaas-stg.certora.com/output/3106/a5f4943cd2987dccab94/?anonymousKey=9428fb1588845c0222c2abe5b00dedd59c925870
+// totalsupply of wrapped should be less than or equal to the underlying balanceOf contract (assuming no external transfer) - solvency
+invariant underTotalAndContractBalanceOfCorrelation(env e)
+    totalSupply(e) <= underlyingBalanceOf(currentContract)
+    {
+        preserved {
+            require underlying() != currentContract;
+        }
+    }
+
+
 // STATUS - verified
 // check correct values update by depositFor()
 rule depositForSpecBasic(env e){