diff --git a/lib/Echidna/Exec.hs b/lib/Echidna/Exec.hs
index 490ff163a..b6b0e370d 100644
--- a/lib/Echidna/Exec.hs
+++ b/lib/Echidna/Exec.hs
@@ -296,10 +296,9 @@ execTxWithCov tx = do
           if size == 0 then pure Nothing else do
             -- IO for making a new vec
             vec <- VMut.new size
-            -- We use -1 for opIx to indicate that the location was not covered
             forM_ [0..size-1] $ \i -> VMut.write vec i (0, 0)
             pure $ Just vec
-        
+
         case maybeCovVec of
           Nothing -> pure ()
           Just vec -> do
@@ -308,14 +307,13 @@ execTxWithCov tx = do
             -- bug in another place, investigate.
             -- ... this should be fixed now, since we use `codeContract` instead
             -- of `contract` for everything; it may be safe to remove this check.
-            when (pc < VMut.length vec) $
+            when (pc < VMut.length vec) $ do
+              VMut.modify (fromJust maybeStatsVec) (\(execQty, revertQty) -> (execQty + 1, revertQty)) opIx
               VMut.read vec pc >>= \case
                 (_, depths, results) | depth < 64 && not (depths `testBit` depth) -> do
                   VMut.write vec pc (opIx, depths `setBit` depth, results `setBit` fromEnum Stop)
-                  VMut.modify (fromJust maybeStatsVec) (\(execQty, revertQty) -> (execQty + 1, revertQty)) opIx
                   writeIORef covContextRef (True, Just (vec, pc))
-                (opIx', depths, results) -> do
-                  VMut.modify (fromJust maybeStatsVec) (\(execQty, revertQty) -> (execQty + 1, revertQty)) opIx'
+                _ -> do
                   modifyIORef' covContextRef $ \(new, _) -> (new, Just (vec, pc))
 
       -- | Get the VM's current execution location
diff --git a/lib/Echidna/Output/Source.hs b/lib/Echidna/Output/Source.hs
index 11490c964..5b31267d7 100644
--- a/lib/Echidna/Output/Source.hs
+++ b/lib/Echidna/Output/Source.hs
@@ -199,8 +199,8 @@ srcMapCov sc covMap statMap contracts = do
                   updateLine (Just (r, q)) = Just ((<> unpackTxResults txResults) r, max q execQty)
                   updateLine Nothing = Just (unpackTxResults txResults, execQty)
                   fileStats = Map.lookup c.runtimeCodehash statMap
-                  idxStats | isJust fileStats = (fromJust fileStats) U.! opIx :: StatsInfo
-                           | otherwise = (fromInteger 0, fromInteger 0) :: StatsInfo
+                  idxStats | isJust fileStats = (fromJust fileStats) U.! opIx
+                           | otherwise        = (fromInteger 0, fromInteger 0)
                   execQty = fst idxStats
                 Nothing -> acc
             Nothing -> acc