diff --git a/.github/workflows/phpunit-sqlite.yml b/.github/workflows/phpunit-sqlite.yml
index 8fa7ff770e099..d7610ff075d10 100644
--- a/.github/workflows/phpunit-sqlite.yml
+++ b/.github/workflows/phpunit-sqlite.yml
@@ -90,6 +90,21 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Enable HEIC support in ImageMagick
+        run: |
+          # The HEIC preview tests need ImageMagick to actually decode HEIC files.
+          # GitHub-hosted runners register the HEIC coder (so the tests are not
+          # skipped) but decoding fails because the libheif delegate is missing
+          # and/or the coder is blocked by ImageMagick's security policy. Install
+          # the delegate and allow the HEIC/HEIF/AVIF coders so decoding succeeds.
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends libheif1 libheif-dev
+          for policy in /etc/ImageMagick-{6,7}/policy.xml; do
+            if [ -f "$policy" ]; then
+              sudo sed -i -E 's/rights="none" pattern="(HEIC|HEIF|AVIF)"/rights="read|write" pattern="\1"/g' "$policy"
+            fi
+          done
+
       - name: Set up dependencies
         run: composer i
 
diff --git a/tests/lib/Preview/HEICTest.php b/tests/lib/Preview/HEICTest.php
index 4853ac9b87963..b21ad6f66c2ec 100644
--- a/tests/lib/Preview/HEICTest.php
+++ b/tests/lib/Preview/HEICTest.php
@@ -27,5 +27,26 @@ protected function setUp(): void {
 			$this->height = 1050;
 			$this->provider = new \OC\Preview\HEIC;
 		}
+
+		$fileName = 'testimage.heic';
+		$sourcePath = \OC::$SERVERROOT . '/tests/data/' . $fileName;
+
+		// queryFormats() only reports that the HEIC coder is registered, not that
+		// ImageMagick can actually decode a HEIC file: the libheif delegate may be
+		// missing or the coder may be disabled by ImageMagick's policy.xml. In that
+		// case decoding throws, the provider returns null and the tests fail instead
+		// of being skipped. Verify a real decode before running the tests.
+		try {
+			(new \Imagick())->readImage($sourcePath . '[0]');
+		} catch (\ImagickException $e) {
+			$this->markTestSkipped('ImageMagick cannot decode HEIC in this environment: ' . $e->getMessage() . '. Skipping tests');
+		}
+
+		parent::setUp();
+
+		$this->imgPath = $this->prepareTestFile($fileName, $sourcePath);
+		$this->width = 1680;
+		$this->height = 1050;
+		$this->provider = new HEIC;
 	}
 }