diff --git a/shell/Ui/BackgroundMedia.qml b/shell/Ui/BackgroundMedia.qml
index 6ca02273..8640769f 100644
--- a/shell/Ui/BackgroundMedia.qml
+++ b/shell/Ui/BackgroundMedia.qml
@@ -8,6 +8,9 @@ Item {
 
   property string path: ""
   property int version: 0
+  // Unversioned images cache by path. A caller whose version changes with every
+  // new file, as the lock's does, may cache too: the version is in the URL.
+  property bool cached: version === 0
   // A caller that knows the size its screen needs, in physical pixels, sets
   // constrainDecode and decodeSize. The image then waits for that size rather
   // than decoding at the file's native size first.
@@ -35,7 +38,7 @@ Item {
       source: !root.constrainDecode || root.decodeSize.width > 0 ? root.imageUrl : ""
       fillMode: Image.PreserveAspectCrop
       asynchronous: true
-      cache: root.version === 0
+      cache: root.cached
       sourceSize.width: root.constrainDecode ? root.decodeSize.width : (root.version > 0 ? width : 0)
       sourceSize.height: root.constrainDecode ? root.decodeSize.height : (root.version > 0 ? height : 0)
     }
diff --git a/shell/plugins/lock/LockView.qml b/shell/plugins/lock/LockView.qml
index 7084fb0f..999a0a04 100644
--- a/shell/plugins/lock/LockView.qml
+++ b/shell/plugins/lock/LockView.qml
@@ -96,6 +96,13 @@ Item {
       anchors.fill: parent
       path: root.loadBackground ? (root.video ? root.videoPosterPath : root.backgroundPath) : ""
       version: root.backgroundVersion
+      // Decode only once sized, at the lock's own size: an unsized first
+      // request decoded the file at its native resolution, then again once
+      // sized. That size is what the lock service keeps decoded ahead of the
+      // lock, so the first frame has the wallpaper.
+      cached: true
+      constrainDecode: true
+      decodeSize: Qt.size(width, height)
     }
 
     MultiEffect {
diff --git a/shell/plugins/lock/Service.qml b/shell/plugins/lock/Service.qml
index 6e1f703e..247495a4 100644
--- a/shell/plugins/lock/Service.qml
+++ b/shell/plugins/lock/Service.qml
@@ -30,6 +30,9 @@ Item {
   property string backgroundPath: ""
   property string videoPosterPath: ""
   property int backgroundVersion: 0
+  // The wallpaper file's mtime and size. The lock caches its wallpaper by
+  // version, so a file overwritten in place must bump the version too.
+  property string backgroundSignature: ""
   property string lastEvent: "init"
   property string lastEventAt: ""
   property bool displaysBlank: false
@@ -407,6 +410,32 @@ Item {
     }
   }
 
+  // The lock only starts decoding its wallpaper once locked, and a machine
+  // suspending right after locking froze that decode partway: waking showed
+  // the password field on a bare background, then the wallpaper popped in.
+  // Keep each screen's lock wallpaper decoded in the image cache ahead of
+  // time, as the lock view requests it (same URL, the screen's logical size,
+  // PreserveAspectCrop), so the lock draws it on its first frame.
+  readonly property string lockWallpaperPath: videoBackground ? videoPosterPath : backgroundPath
+  readonly property string lockWallpaperUrl: lockWallpaperPath && !Util.isVideoPath(lockWallpaperPath)
+    ? Util.fileUrl(lockWallpaperPath) + (backgroundVersion ? "?v=" + backgroundVersion : "")
+    : ""
+
+  Variants {
+    model: Quickshell.screens
+
+    Image {
+      required property var modelData
+      visible: false
+      source: root.lockWallpaperUrl
+      sourceSize.width: modelData.width
+      sourceSize.height: modelData.height
+      fillMode: Image.PreserveAspectCrop
+      asynchronous: true
+      cache: true
+    }
+  }
+
   Timer {
     id: fingerprintRetryTimer
     interval: 250
@@ -416,14 +445,20 @@ Item {
 
   Process {
     id: readlinkProc
-    command: ["readlink", "-f", root.currentBackgroundLink]
+    command: ["bash", "-c", "path=$(readlink -f -- \"$1\") && printf '%s\\n%s\\n' \"$path\" \"$(stat -Lc %Y:%s -- \"$path\" 2>/dev/null)\"", "_", root.currentBackgroundLink]
     stdout: StdioCollector {
       waitForEnd: true
       onStreamFinished: {
-        var next = String(text || "").trim()
+        var lines = String(text || "").split("\n")
+        var next = String(lines[0] || "").trim()
+        var signature = String(lines[1] || "").trim()
         if (next !== root.backgroundPath) {
           root.videoPosterPath = ""
           root.backgroundPath = next
+          root.backgroundSignature = signature
+          root.backgroundVersion += 1
+        } else if (signature !== root.backgroundSignature) {
+          root.backgroundSignature = signature
           root.backgroundVersion += 1
         }
         root.refreshPoster()
diff --git a/test/shell.d/lock-wallpaper-preload-test.sh b/test/shell.d/lock-wallpaper-preload-test.sh
new file mode 100644
index 00000000..8d0cc46a
--- /dev/null
+++ b/test/shell.d/lock-wallpaper-preload-test.sh
@@ -0,0 +1,42 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+run_node_test <<'JS'
+const fs = require('fs')
+const read = (file) => fs.readFileSync(path.join(root, file), 'utf8')
+const media = read('shell/Ui/BackgroundMedia.qml')
+const view = read('shell/plugins/lock/LockView.qml')
+const service = read('shell/plugins/lock/Service.qml')
+
+// The lock draws its wallpaper on the first frame only if the image it asks
+// for is already in the cache: same URL, same requested size, same fill mode.
+assert(
+  media.includes('property bool cached: version === 0') && media.includes('cache: root.cached'),
+  'background media caches unversioned images, and versioned ones on request'
+)
+assert(
+  /version: root\.backgroundVersion\s*(\/\/.*\n\s*)*cached: true\s*constrainDecode: true\s*decodeSize: Qt\.size\(width, height\)/.test(view),
+  'the lock wallpaper waits for its size and reads from the cache'
+)
+assert(
+  service.includes('readonly property string lockWallpaperPath: videoBackground ? videoPosterPath : backgroundPath') &&
+    service.includes('? Util.fileUrl(lockWallpaperPath) + (backgroundVersion ? "?v=" + backgroundVersion : "")') &&
+    media.includes('Util.fileUrl(path) + (version ? "?v=" + version : "")'),
+  'the lock service preloads the exact URL the lock view requests'
+)
+assert(
+  /model: Quickshell\.screens\s*Image \{\s*required property var modelData\s*visible: false\s*source: root\.lockWallpaperUrl\s*sourceSize\.width: modelData\.width\s*sourceSize\.height: modelData\.height\s*fillMode: Image\.PreserveAspectCrop\s*asynchronous: true\s*cache: true/.test(service),
+  'the lock service keeps each screen\'s lock wallpaper decoded at the lock\'s size and fill'
+)
+
+// A wallpaper overwritten in place keeps its path, so the version, which is
+// part of the cached URL, follows the file's mtime and size as well.
+assert(
+  service.includes('stat -Lc %Y:%s') &&
+    /\} else if \(signature !== root\.backgroundSignature\) \{\s*root\.backgroundSignature = signature\s*root\.backgroundVersion \+= 1/.test(service),
+  'an overwritten wallpaper bumps the lock wallpaper version'
+)
+JS