diff --git a/source/build/src/clip.cpp b/source/build/src/clip.cpp
index a25dd0c9d..e0d8a6a23 100644
--- a/source/build/src/clip.cpp
+++ b/source/build/src/clip.cpp
@@ -2477,7 +2477,7 @@ restart_grand:
             // try and see whether this sprite's picnum has sector-like clipping data
             i = pictoidx[spr->picnum];
             // handle sector-like floor sprites separately
-            while (i>=0 && (cstat&32) != (clipmapinfo.sector[sectq[clipinfo[i].qbeg]].CM_CSTAT&32))
+            while ((&clipmapinfo != nullptr) && i>=0 && (cstat&32) != (clipmapinfo.sector[sectq[clipinfo[i].qbeg]].CM_CSTAT&32))
                 i = clipinfo[i].next;
             if (i>=0 && clipspritenum<MAXCLIPNUM)
             {