diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index 4a79c8543..6b52eba9b 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -51,6 +51,7 @@ Fixed
 - Fixed crashes when opening an empty URL (e.g. via pasting).
 - Fixed validation of duplicate values in `hints -> chars`.
 - Fixed crash when PDF.js was partially installed.
+- Fixed crash when XDG_DOWNLOAD_DIR was not an absolute path.
 
 v0.5.1
 ------
diff --git a/qutebrowser/browser/downloads.py b/qutebrowser/browser/downloads.py
index 667e8e7a2..c3c6203d9 100644
--- a/qutebrowser/browser/downloads.py
+++ b/qutebrowser/browser/downloads.py
@@ -534,6 +534,22 @@ class DownloadItem(QObject):
             self._filename = create_full_filename(
                 self.basename, os.path.join(download_dir(), filename))
 
+        # At this point, we have a misconfigured XDG_DOWNLOAd_DIR, as
+        # download_dir() + filename is still no absolute path.
+        # The config value is checked for "absoluteness", but
+        # ~/.config/user-dirs.dirs may be misconfigured and a non-absolute path
+        # may be set for XDG_DOWNLOAD_DIR
+        if self._filename is None:
+            message.error(
+                self._win_id,
+                "XDG_DOWNLOAD_DIR points to a relative path - please check"
+                " your ~/.config/user-dirs.dirs. The download is saved in"
+                " your home directory.",
+            )
+            # fall back to $HOME as download_dir
+            self._filename = create_full_filename(
+                self.basename, os.path.expanduser(os.path.join('~', filename)))
+
         self.basename = os.path.basename(self._filename)
         last_used_directory = os.path.dirname(self._filename)