diff --git a/Source/drlg_l1.cpp b/Source/drlg_l1.cpp
index aac01851f..ae8eadf5f 100644
--- a/Source/drlg_l1.cpp
+++ b/Source/drlg_l1.cpp
@@ -1307,11 +1307,9 @@ static void InitL5Dungeon()
 
 static void L5ClearFlags()
 {
-	int i, j;
-
-	for (j = 0; j < DMAXY; j++) {
-		for (i = 0; i < DMAXX; i++) {
-			L5dflags[i][j] &= 0xBF;
+	for (int j = 0; j < DMAXY; j++) {
+		for (int i = 0; i < DMAXX; i++) {
+			L5dflags[i][j] &= ~DLRG_CHAMBER;
 		}
 	}
 }
@@ -2628,7 +2626,7 @@ static void DRLG_L5(lvl_entry entry)
 
 	for (j = 0; j < DMAXY; j++) {
 		for (i = 0; i < DMAXX; i++) {
-			if (L5dflags[i][j] & 0x7F)
+			if (L5dflags[i][j] & ~DLRG_PROTECTED)
 				DRLG_PlaceDoor(i, j);
 		}
 	}
diff --git a/Source/lighting.cpp b/Source/lighting.cpp
index 843a72b30..1e323c23b 100644
--- a/Source/lighting.cpp
+++ b/Source/lighting.cpp
@@ -668,7 +668,7 @@ void DoVision(int nXPos, int nYPos, int nRadius, bool doautomap, bool visible)
 
 	if (nXPos >= 0 && nXPos <= MAXDUNX && nYPos >= 0 && nYPos <= MAXDUNY) {
 		if (doautomap) {
-			if (dFlags[nXPos][nYPos] >= 0) {
+			if (dFlags[nXPos][nYPos] != 0) {
 				SetAutomapView({ nXPos, nYPos });
 			}
 			dFlags[nXPos][nYPos] |= BFLAG_EXPLORED;
@@ -729,7 +729,7 @@ void DoVision(int nXPos, int nYPos, int nRadius, bool doautomap, bool visible)
 					    || (x2adj + nCrawlX >= 0 && x2adj + nCrawlX < MAXDUNX && y2adj + nCrawlY >= 0 && y2adj + nCrawlY < MAXDUNY
 					        && !nBlockTable[dPiece[x2adj + nCrawlX][y2adj + nCrawlY]])) {
 						if (doautomap) {
-							if (dFlags[nCrawlX][nCrawlY] >= 0) {
+							if (dFlags[nCrawlX][nCrawlY] != 0) {
 								SetAutomapView({ nCrawlX, nCrawlY });
 							}
 							dFlags[nCrawlX][nCrawlY] |= BFLAG_EXPLORED;