diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index cc4a5883e..1bb0acfe1 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -1438,6 +1438,7 @@ using #loot -> 'i'n to put multiple items into a shop-owned container would
 	'q' to not sell the current one or any beyond it, but the sell vs
 	don't-sell state was being reset for each item so 'a' and 'q' didn't
 	stick beyond the current one
+join wall "spines" with walls of water and lava
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository
diff --git a/src/mkmaze.c b/src/mkmaze.c
index 5acf97cc6..040d466f3 100644
--- a/src/mkmaze.c
+++ b/src/mkmaze.c
@@ -40,6 +40,7 @@ staticfn boolean is_exclusion_zone(xint16, coordxy, coordxy);
         }                                                        \
     } while (0)
 
+/* used to determine if wall spines can join this location */
 staticfn int
 iswall(coordxy x, coordxy y)
 {
@@ -49,9 +50,11 @@ iswall(coordxy x, coordxy y)
         return 0;
     type = levl[x][y].typ;
     return (IS_WALL(type) || IS_DOOR(type)
+            || type == LAVAWALL || type == WATER
             || type == SDOOR || type == IRONBARS);
 }
 
+/* used to determine if wall spines can join this location */
 staticfn int
 iswall_or_stone(coordxy x, coordxy y)
 {