diff --git a/Tupfile.lua b/Tupfile.lua
index ae0b23d4..97efee28 100644
--- a/Tupfile.lua
+++ b/Tupfile.lua
@@ -63,15 +63,7 @@ rule(
 
 -- Smogdex social images
 
-local input = {}
-for file in iter(glob{"newsrc/models/*"}) do
-    local sd = spritedata(tup.base(file))
-    if sd.data.b or sd.data.s then
-        goto continue
-    end
-    input += file
-    ::continue::
-end
+local input = spriteglob("newsrc/models/*", {b = false, s = false})
 
 foreach_rule(
     input,
@@ -128,10 +120,11 @@ for file in iter(dexOutput) do
 end
 
 local dexMissing = {}
-for file in iter(glob{"newsrc/sprites/gen5/*.gif", "newsrc/models/*.gif"}) do
+for file in iter(spriteglob(
+                     {"newsrc/sprites/gen5/*.gif", "newsrc/models/*.gif"},
+                     {b = false, s = false})) do
     local base = tup.base(file)
-    local sd = spritedata(base)
-    if sd.data.b or sd.data.s or dexSet[base] then
+    if dexSet[base] then
         goto continue
     end
     dexMissing += file
diff --git a/util/lua-ext.lua b/util/lua-ext.lua
index dead628b..808a06ac 100644
--- a/util/lua-ext.lua
+++ b/util/lua-ext.lua
@@ -64,3 +64,23 @@ function flatten(arr)
     flatten(arr)
     return result
 end
+
+-- Adapted from https://stackoverflow.com/a/53038524
+function filter(t, fn)
+    local j, n = 1, #t
+
+    for i=1,n do
+        if fn(t[i]) then
+            -- Move i's kept value to j's position, if it's not already there.
+            if (i ~= j) then
+                t[j] = t[i]
+                t[i] = nil
+            end
+            j = j + 1 -- Increment position of where we'll place the next kept value.
+        else
+            t[i] = nil
+        end
+    end
+
+    return t
+end
diff --git a/util/sprites.lua b/util/sprites.lua
index d18b6d45..6a036a11 100644
--- a/util/sprites.lua
+++ b/util/sprites.lua
@@ -13,3 +13,19 @@ function spritedata(basename)
     end
     return result
 end
+
+function spriteglob(pat, flagspec)
+    local results = glob(pat)
+    local function fn(filename)
+        local sd = spritedata(tup.base(filename))
+        for k, v in pairs(flagspec) do
+            -- Make sure both are booleans
+            if not not v ~= not not sd.data[k] then
+                return false
+            end
+        end
+        return true
+    end
+    filter(results, fn)
+    return results
+end