diff --git a/data/core/terrain-graphics/tiles.cfg b/data/core/terrain-graphics/tiles.cfg
index d798f5d29bb..6b16ba10b7e 100644
--- a/data/core/terrain-graphics/tiles.cfg
+++ b/data/core/terrain-graphics/tiles.cfg
@@ -84,8 +84,8 @@
 #define OVERLAY_LF TERRAINLIST LAYER FLAG IMAGESTEM
     {OVERLAY_PLF ({TERRAINLIST}) 100 ({LAYER}) ({FLAG}) ({IMAGESTEM})}
 #enddef
-#define OVERLAY_PF TERRAINLIST PROB FLAG IMAGESTEM
-    {OVERLAY_PLF ({TERRAINLIST}) ({PROB}) 0 ({FLAG}) ({IMAGESTEM})}
+#define OVERLAY_PF TERRAINLIST FRAC FLAG IMAGESTEM
+    {OVERLAY_PLF ({TERRAINLIST}) ({FRAC}) 0 ({FLAG}) ({IMAGESTEM})}
 #enddef
 #define OVERLAY_F TERRAINLIST FLAG IMAGESTEM
     {OVERLAY_PLF ({TERRAINLIST}) 100 0 ({FLAG}) ({IMAGESTEM})}
diff --git a/data/tools/wesnoth/wmltools.py b/data/tools/wesnoth/wmltools.py
index 73e7e8b8f63..589c1c5b3d4 100644
--- a/data/tools/wesnoth/wmltools.py
+++ b/data/tools/wesnoth/wmltools.py
@@ -145,7 +145,7 @@ def formaltype(f):
     # Deduce the expected type of the formal
     if f.startswith("_"):
         f = f[1:]
-    if f in ("SIDE", "X", "Y", "RED", "GREEN", "BLUE", "TURN", "RADIUS") or f.endswith("NUMBER") or f.endswith("AMOUNT") or f.endswith("COST") or f.endswith("_X") or f.endswith("_Y") or f.endswith("_INCREMENT") or f.endswith("_FACTOR"):
+    if f in ("SIDE", "X", "Y", "RED", "GREEN", "BLUE", "TURN", "RADIUS", "PROB") or f.endswith("NUMBER") or f.endswith("AMOUNT") or f.endswith("COST") or f.endswith("_X") or f.endswith("_Y") or f.endswith("_INCREMENT") or f.endswith("_FACTOR"):
         ftype = "numeric"
     elif f in ("POSITION",):
         ftype = "position"