diff --git a/contracts/OverlayV1Market.sol b/contracts/OverlayV1Market.sol
index 6da34c96..f76f0afa 100644
--- a/contracts/OverlayV1Market.sol
+++ b/contracts/OverlayV1Market.sol
@@ -342,18 +342,7 @@ contract OverlayV1Market is IOverlayV1Market {
 
             // subtract unwound open interest from the side's aggregate oi value
             // and decrease number of oi shares issued
-            // NOTE: use subFloor to avoid reverts with oi rounding issues
-            if (pos.isLong) {
-                oiLong = oiLong.subFloor(
-                    pos.oiCurrent(fraction, oiTotalOnSide, oiTotalSharesOnSide)
-                );
-                oiLongShares -= pos.oiSharesCurrent(fraction);
-            } else {
-                oiShort = oiShort.subFloor(
-                    pos.oiCurrent(fraction, oiTotalOnSide, oiTotalSharesOnSide)
-                );
-                oiShortShares -= pos.oiSharesCurrent(fraction);
-            }
+            _reduceOIAndOIShares(pos, fraction);
 
             // register the amount to be minted/burned
             // capPayoff prevents overflow reverts with int256 cast
@@ -444,18 +433,7 @@ contract OverlayV1Market is IOverlayV1Market {
 
             // subtract liquidated open interest from the side's aggregate oi value
             // and decrease number of oi shares issued
-            // NOTE: use subFloor to avoid reverts with oi rounding issues
-            if (pos.isLong) {
-                oiLong = oiLong.subFloor(
-                    pos.oiCurrent(fraction, oiTotalOnSide, oiTotalSharesOnSide)
-                );
-                oiLongShares -= pos.oiSharesCurrent(fraction);
-            } else {
-                oiShort = oiShort.subFloor(
-                    pos.oiCurrent(fraction, oiTotalOnSide, oiTotalSharesOnSide)
-                );
-                oiShortShares -= pos.oiSharesCurrent(fraction);
-            }
+            _reduceOIAndOIShares(pos, fraction);
 
             // register the amount to be burned
             _registerMintOrBurn(int256(value) - int256(cost) - int256(marginToBurn));
@@ -748,6 +726,23 @@ contract OverlayV1Market is IOverlayV1Market {
         return minted;
     }
 
+    /// @notice subtract open interest from the side's aggregate oi value
+    /// @notice and decrease number of oi shares issued
+    function _reduceOIAndOIShares(Position.Info memory pos, uint256 fraction) internal {
+        // NOTE: use subFloor to avoid reverts with oi rounding issues
+        if (pos.isLong) {
+            oiLong = oiLong.subFloor(
+                pos.oiCurrent(fraction, oiTotalOnSide, oiTotalSharesOnSide)
+            );
+            oiLongShares -= pos.oiSharesCurrent(fraction);
+        } else {
+            oiShort = oiShort.subFloor(
+                pos.oiCurrent(fraction, oiTotalOnSide, oiTotalSharesOnSide)
+            );
+            oiShortShares -= pos.oiSharesCurrent(fraction);
+        }
+    }
+
     /// @notice Updates the market for funding changes to open interest
     /// @notice since last time market was interacted with
     function _payFunding() private {