diff --git a/source/compose.manager/include/Util.php b/source/compose.manager/include/Util.php
index e50b030f..3fdf3818 100644
--- a/source/compose.manager/include/Util.php
+++ b/source/compose.manager/include/Util.php
@@ -3536,7 +3536,7 @@ private function getMainFileServices(): array
             return [];
         }
 
-        $cmd = "docker compose " . $this->buildComposeFileFlags();
+        $cmd = "docker compose " . $this->buildComposeFileFlagsWithoutManagedOverride();
         $envFlag = $this->buildEnvFileFlag();
         if ($envFlag !== '') {
             $cmd .= " " . $envFlag;
@@ -3553,6 +3553,46 @@ private function getMainFileServices(): array
         }));
     }
 
+    /**
+     * The -f flags for this stack, leaving out the plugin-managed override and
+     * the icon override generated from it.
+     *
+     * Both files hold only labels. An entry for a service the compose file no
+     * longer has defines a service with no image, and compose refuses the
+     * whole project over it ("has neither an image nor a build context"), so
+     * they must be left out when asking which services are valid.
+     *
+     * With default file discovery, compose would find the managed override by
+     * itself: it sits next to the compose file under the override name
+     * compose looks for. So the files are named with -f in that mode too,
+     * from the same project directory compose would use.
+     *
+     * @return string
+     */
+    private function buildComposeFileFlagsWithoutManagedOverride(): string
+    {
+        $leftOut = [];
+        foreach ([$this->overrideInfo->getProjectOverridePath(), $this->getIconNormalizationOverridePath()] as $path) {
+            if ($path !== null) {
+                $leftOut[$this->normalizeComposeFilePath($path)] = true;
+            }
+        }
+
+        $flags = [];
+        if ($this->useDefaultComposeFileDiscovery()) {
+            $flags[] = '--project-directory ' . escapeshellarg($this->composeSource);
+        }
+        foreach ($this->getComposeFilePaths() as $filePath) {
+            if (isset($leftOut[$this->normalizeComposeFilePath($filePath)])) {
+                continue;
+            }
+            if (is_file($filePath)) {
+                $flags[] = '-f ' . escapeshellarg($filePath);
+            }
+        }
+        return implode(' ', $flags);
+    }
+
     /**
      * Build the common compose CLI arguments for this stack.
      *
diff --git a/tests/unit/PruneOrphanOverrideServicesTest.php b/tests/unit/PruneOrphanOverrideServicesTest.php
new file mode 100644
index 00000000..89902529
--- /dev/null
+++ b/tests/unit/PruneOrphanOverrideServicesTest.php
@@ -0,0 +1,141 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ComposeManager\Tests;
+
+use PluginTests\TestCase;
+
+require_once '/usr/local/emhttp/plugins/compose.manager/include/Util.php';
+
+/**
+ * StackInfo::pruneOrphanOverrideServices() with a stand-in docker CLI on PATH.
+ *
+ * The stand-in behaves like docker compose does for `config --services`: it
+ * fails when it is given the managed override with an entry for a service
+ * that has no image, and otherwise prints the compose file's services. Given
+ * no -f flag, it finds compose.override.yaml in the project directory by
+ * itself, as compose does.
+ */
+final class PruneOrphanOverrideServicesTest extends TestCase
+{
+    private string $root;
+    private string $bin;
+    private string $originalPath;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        \StackInfo::clearCache();
+        $this->root = $this->createTempDir();
+        $this->bin = $this->createTempDir();
+        $this->originalPath = (string) getenv('PATH');
+
+        file_put_contents($this->bin . '/docker', <<<'SH'
+#!/bin/bash
+# Record the call, then answer like docker compose config --services.
+printf '%s\n' "$*" >> "$(dirname "$0")/calls.log"
+refuse() {
+  echo 'service "gone" has neither an image nor a build context specified: invalid compose project' >&2
+  exit 1
+}
+project_directory=''
+files_named=no
+previous=''
+for arg in "$@"; do
+  case "$arg" in
+    *override*) refuse ;;
+  esac
+  if [ "$previous" = '--project-directory' ]; then
+    project_directory="$arg"
+  fi
+  if [ "$previous" = '-f' ]; then
+    files_named=yes
+  fi
+  previous="$arg"
+done
+if [ "$files_named" = no ] && [ -f "$project_directory/compose.override.yaml" ]; then
+  refuse
+fi
+echo web
+SH);
+        chmod($this->bin . '/docker', 0755);
+        putenv('PATH=' . $this->bin . ':' . $this->originalPath);
+    }
+
+    protected function tearDown(): void
+    {
+        putenv('PATH=' . $this->originalPath);
+        parent::tearDown();
+    }
+
+    public function testServiceNoLongerInTheComposeFileIsPrunedFromTheManagedOverride(): void
+    {
+        $stackDir = $this->root . '/mystack';
+        mkdir($stackDir);
+        file_put_contents($stackDir . '/compose.yaml', "services:\n  web:\n    image: traefik/whoami\n");
+        $stack = \StackInfo::fromProject($this->root, 'mystack');
+        $override = (string) $stack->getOverridePath();
+        file_put_contents(
+            $override,
+            "services:\n  web:\n    labels:\n      net.unraid.docker.webui: http://x\n"
+            . "  gone:\n    labels:\n      net.unraid.docker.webui: http://y\n"
+        );
+        \StackInfo::clearCache();
+        $stack = \StackInfo::fromProject($this->root, 'mystack');
+
+        $result = $stack->pruneOrphanOverrideServices();
+
+        $this->assertSame(['gone'], $result['removed']);
+        $content = (string) file_get_contents($override);
+        $this->assertStringNotContainsString('gone', $content);
+        $this->assertStringContainsString('web', $content);
+        // The services were asked for without the override.
+        $this->assertStringNotContainsString($override, (string) file_get_contents($this->bin . '/calls.log'));
+    }
+
+    public function testServiceIsPrunedWhenTheStackUsesDefaultFileDiscovery(): void
+    {
+        $stackDir = $this->root . '/mystack';
+        mkdir($stackDir);
+        file_put_contents($stackDir . '/compose.yaml', "services:\n  web:\n    image: traefik/whoami\n");
+        file_put_contents($stackDir . '/use_default_compose_files', 'true');
+        $stack = \StackInfo::fromProject($this->root, 'mystack');
+        $this->assertTrue($stack->useDefaultComposeFileDiscovery());
+        $override = (string) $stack->getOverridePath();
+        $this->assertSame($stackDir . '/compose.override.yaml', $override);
+        file_put_contents(
+            $override,
+            "services:\n  web:\n    labels:\n      net.unraid.docker.webui: http://x\n"
+            . "  gone:\n    labels:\n      net.unraid.docker.webui: http://y\n"
+        );
+        \StackInfo::clearCache();
+        $stack = \StackInfo::fromProject($this->root, 'mystack');
+
+        $result = $stack->pruneOrphanOverrideServices();
+
+        $this->assertSame(['gone'], $result['removed']);
+        $this->assertStringNotContainsString('gone', (string) file_get_contents($override));
+        // The compose file was named, so compose could not pick up the override by itself.
+        $calls = (string) file_get_contents($this->bin . '/calls.log');
+        $this->assertStringContainsString("-f {$stackDir}/compose.yaml", $calls);
+        $this->assertStringContainsString("--project-directory {$stackDir}", $calls);
+    }
+
+    public function testOverrideWithOnlyCurrentServicesIsLeftAlone(): void
+    {
+        $stackDir = $this->root . '/mystack';
+        mkdir($stackDir);
+        file_put_contents($stackDir . '/compose.yaml', "services:\n  web:\n    image: traefik/whoami\n");
+        $stack = \StackInfo::fromProject($this->root, 'mystack');
+        $override = (string) $stack->getOverridePath();
+        $content = "services:\n  web:\n    labels:\n      net.unraid.docker.webui: http://x\n";
+        file_put_contents($override, $content);
+        \StackInfo::clearCache();
+
+        $result = \StackInfo::fromProject($this->root, 'mystack')->pruneOrphanOverrideServices();
+
+        $this->assertFalse($result['changed']);
+        $this->assertSame($content, file_get_contents($override));
+    }
+}