diff --git a/qutebrowser/utils/version.py b/qutebrowser/utils/version.py
index 3f6b9c8d0..0a3d35cfb 100644
--- a/qutebrowser/utils/version.py
+++ b/qutebrowser/utils/version.py
@@ -210,7 +210,7 @@ def _pdfjs_version():
     else:
         pdfjs_file = pdfjs_file.decode('utf-8')
         version_re = re.compile(
-            r"^(PDFJS\.version|var pdfjsVersion) = '([^']+)';$", re.MULTILINE)
+            r"^ *(PDFJS\.version|var pdfjsVersion) = '([^']+)';$", re.MULTILINE)
 
         match = version_re.search(pdfjs_file)
         if not match: