diff --git a/source/exhumed/src/lighting.cpp b/source/exhumed/src/lighting.cpp
index e06ff7d5b..47386ce08 100644
--- a/source/exhumed/src/lighting.cpp
+++ b/source/exhumed/src/lighting.cpp
@@ -589,8 +589,8 @@ void AddFlow(int nSprite, int a, int b)
 
         sFlowInfo[nFlow].field_14 = (tilesiz[nPic].x << 14) - 1;
         sFlowInfo[nFlow].field_18 = (tilesiz[nPic].y << 14) - 1;
-        sFlowInfo[nFlow].field_C  = (-Sin(nAngle + 512)) * a;
-        sFlowInfo[nFlow].field_10 = (-Sin(nAngle)) * a;
+        sFlowInfo[nFlow].field_C  = -Cos(nAngle) * a;
+        sFlowInfo[nFlow].field_10 = Sin(nAngle) * a;
     }
     else
     {
@@ -608,8 +608,8 @@ void AddFlow(int nSprite, int a, int b)
 
         sFlowInfo[nFlow].field_14 = (tilesiz[nPic].x * wall[var_18].xrepeat) << 8;
         sFlowInfo[nFlow].field_18 = (tilesiz[nPic].y * wall[var_18].yrepeat) << 8;
-        sFlowInfo[nFlow].field_C = (-Sin(nAngle + 512)) * a;
-        sFlowInfo[nFlow].field_10 = (-Sin(nAngle)) * a;
+        sFlowInfo[nFlow].field_C = -Cos(nAngle) * a;
+        sFlowInfo[nFlow].field_10 = Sin(nAngle) * a;
     }
 
     sFlowInfo[nFlow].field_8 = 0;