diff --git a/Source/missiles.cpp b/Source/missiles.cpp
index 42f87e3cb..135dd8a23 100644
--- a/Source/missiles.cpp
+++ b/Source/missiles.cpp
@@ -1322,6 +1322,7 @@ void AddRndTeleport(int mi, int sx, int sy, int dx, int dy, int midir, char mien
 			UseMana(id, SPL_RNDTELEPORT);
 	} else {
 		pn = dObject[dx][dy] - 1;
+		// BUGFIX: should only run magic circle check if dObject[dx][dy] is non-zero.
 		if (object[pn]._otype == OBJ_MCIRCLE1 || object[pn]._otype == OBJ_MCIRCLE2) {
 			missile[mi]._mix = dx;
 			missile[mi]._miy = dy;