diff --git a/libsquoosh/src/codecs.ts b/libsquoosh/src/codecs.ts
index 6fdb5e82..e97c753c 100644
--- a/libsquoosh/src/codecs.ts
+++ b/libsquoosh/src/codecs.ts
@@ -282,7 +282,7 @@ export const codecs = {
   webp: {
     name: 'WebP',
     extension: 'webp',
-    detectors: [/^RIFF....WEBPVP8[LX ]/],
+    detectors: [/^RIFF....WEBPVP8[LX ]/s],
     dec: () => instantiateEmscriptenWasm(webpDec, webpDecWasm),
     enc: () => instantiateEmscriptenWasm(webpEnc, webpEncWasm),
     defaultEncoderOptions: {
diff --git a/src/client/lazy-app/util/index.ts b/src/client/lazy-app/util/index.ts
index 24a21f93..f7152182 100644
--- a/src/client/lazy-app/util/index.ts
+++ b/src/client/lazy-app/util/index.ts
@@ -95,7 +95,7 @@ const magicNumberMapInput = [
   [/^I I/, 'image/tiff'],
   [/^II*/, 'image/tiff'],
   [/^MM\x00*/, 'image/tiff'],
-  [/^RIFF....WEBPVP8[LX ]/, 'image/webp'],
+  [/^RIFF....WEBPVP8[LX ]/s, 'image/webp'],
   [/^\xF4\xFF\x6F/, 'image/webp2'],
   [/^\x00\x00\x00 ftypavif\x00\x00\x00\x00/, 'image/avif'],
   [/^\xff\x0a/, 'image/jxl'],