diff --git a/doc/styling.md b/doc/styling.md
index 608cd10..04ae390 100644
--- a/doc/styling.md
+++ b/doc/styling.md
@@ -45,8 +45,8 @@ See [the Luanti documentation](https://api.luanti.org/formspec/#styling-formspec
 for a list of valid property names and values. Flow accepts numbers and
 booleans as property values where applicable.
 
-**Warning:** Flow does not currently support styles that change the element
-size, like `font_size` for labels and `size` for lists.
+**Warning:** Styles that change the size of the element are currently only
+supported on `gui.List` (notably `font_size` on labels won't work properly)
 
 ## Separate style elements
 
@@ -70,3 +70,7 @@ gui.Button{
 ```
 
 The `Style` and `StyleType` elements are invisible and won't affect padding.
+
+**Warning:** `gui.Style` and `gui.StyleType` do not support *any* styles that
+change the element size, such as `font_size` for labels and `size` and `spacing`
+lists.
diff --git a/expand.lua b/expand.lua
index 7bf165d..f735d27 100644
--- a/expand.lua
+++ b/expand.lua
@@ -17,7 +17,8 @@
 -- along with this program.  If not, see <https://www.gnu.org/licenses/>.
 --
 
-local DEFAULT_SPACING, LABEL_OFFSET, invisible_elems = ...
+local DEFAULT_SPACING, LABEL_OFFSET, get_and_fill_in_sizes,
+    invisible_elems = ...
 local align_types = {}
 
 function align_types.fill(node, x, w, extra_space)
@@ -147,8 +148,7 @@ local function expand(box)
             if not invisible_elems[node.type] then
                 local width, height = node.w or 0, node.h or 0
                 if node.type == "list" then
-                    width = width * 1.25 - 0.25
-                    height = height * 1.25 - 0.25
+                    width, height = get_and_fill_in_sizes(node)
                 end
                 local padding_x2 = (node.padding or 0) * 2
                 align_types[node.align_h or "auto"](node, "x", "w", box.w -
@@ -191,8 +191,10 @@ local function expand(box)
             end
 
             if node.type == "list" then
-                width = width * 1.25 - 0.25
-                height = height * 1.25 - 0.25
+                width, height = get_and_fill_in_sizes(node)
+                if y == "x" then
+                    width, height = height, width
+                end
             end
             free_space = free_space - width - (node.padding or 0) * 2 -
                 (y == "x" and node._padding_top or 0)
diff --git a/init.lua b/init.lua
index e6c07a5..674ae9b 100644
--- a/init.lua
+++ b/init.lua
@@ -26,7 +26,7 @@ local apply_padding, get_and_fill_in_sizes, set_current_lang,
     dofile(modpath .. "/layout.lua")
 
 local expand = assert(loadfile(modpath .. "/expand.lua"))(
-    DEFAULT_SPACING, LABEL_OFFSET, invisible_elems
+    DEFAULT_SPACING, LABEL_OFFSET, get_and_fill_in_sizes, invisible_elems
 )
 
 local parse_callbacks = dofile(modpath .. "/input.lua")
diff --git a/layout.lua b/layout.lua
index 6bd42ed..3db9240 100644
--- a/layout.lua
+++ b/layout.lua
@@ -105,9 +105,32 @@ end
 
 local size_getters = {}
 
+local function parse_v2f(str, default_x, default_y)
+    if str and type(str) == "string" then
+        local x, y = str:match("^%s-(%d+)%s-,%s-(%d+)%s-$")
+        return tonumber(x) or default_x, tonumber(y) or default_y
+    end
+
+    return default_x, default_y
+end
+
 local function get_and_fill_in_sizes(node)
     if node.type == "list" then
-        return node.w * 1.25 - 0.25, node.h * 1.25 - 0.25
+        if node._flow_w and node._flow_h then
+            return node._flow_w, node._flow_h
+        end
+
+        local style = node.style
+        local slot_w, slot_h = parse_v2f(style and style.size, 1, 1)
+        local spacing_w, spacing_h = parse_v2f(style and style.spacing, 0.25, 0.25)
+
+        local w = node.w * (slot_w + spacing_w) - spacing_w
+        local h = node.h * (slot_h + spacing_h) - spacing_h
+
+        -- Cache calculated size so we don't have to parse the list style again
+        node._flow_w, node._flow_h = w, h
+
+        return w, h
     end
 
     if node.w and node.h then