diff --git a/CHANGELOG.md b/CHANGELOG.md
index 747829a..9bf1ec6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ It's about time I started a changelog! This will serve from now on as the main c
      - If you encounter any other issues with it over large areas (particularly 2000x150x2000 and larger), please let me know
  - Bugfix: Fix obscure crash in calls to `human_size` ("unknown" will now be returned if passed junk)
  - `//many` can now be used with commands with no arguments.
+ - `//fillcaves`: Treat liquids as air when filling caves in
 
 ## v1.10 (16th January 2021)
  - `//maze`: Fix some parts of generated mazes staying solid
diff --git a/worldeditadditions/lib/fillcaves.lua b/worldeditadditions/lib/fillcaves.lua
index debb983..5a1706f 100644
--- a/worldeditadditions/lib/fillcaves.lua
+++ b/worldeditadditions/lib/fillcaves.lua
@@ -27,7 +27,7 @@ function worldeditadditions.fillcaves(pos1, pos2, node_name)
 			for y = pos2.y, pos1.y, -1 do
 				local i = area:index(x, y, z)
 				
-				local is_air = worldeditadditions.is_airlike(data[i])
+				local is_air = worldeditadditions.is_airlike(data[i]) or worldeditadditions.is_liquidlike(data[i])
 				local is_ignore = data[i] == node_id_ignore
 				
 				-- If the previous node was air and this one isn't, then we've found the top level