diff --git a/pkgs/development/libraries/libadwaita/default.nix b/pkgs/development/libraries/libadwaita/default.nix
index bd51a9a1245e..d38ad7e0899b 100644
--- a/pkgs/development/libraries/libadwaita/default.nix
+++ b/pkgs/development/libraries/libadwaita/default.nix
@@ -24,7 +24,7 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "libadwaita";
-  version = "1.5.3";
+  version = "1.6.beta";
 
   outputs = [ "out" "dev" "devdoc" ];
   outputBin = "devdoc"; # demo app
@@ -34,7 +34,7 @@ stdenv.mkDerivation (finalAttrs: {
     owner = "GNOME";
     repo = "libadwaita";
     rev = finalAttrs.version;
-    hash = "sha256-NCQCd/QnJg2fEI6q5ys8HQXinGnKaoxhMUHd8rwxAmk=";
+    hash = "sha256-YcmvVhNHOcqpazjKXNIoy8fREgZaMFswgO32PX750A4=";
   };
 
   depsBuildBuild = [
@@ -93,7 +93,9 @@ stdenv.mkDerivation (finalAttrs: {
       # AdwSettings needs to be initialized from “org.gnome.desktop.interface” GSettings schema when portal is not used for color scheme.
       # It will not actually be used since the “color-scheme” key will only have been introduced in GNOME 42, falling back to detecting theme name.
       # See adw_settings_constructed function in https://gitlab.gnome.org/GNOME/libadwaita/commit/60ec69f0a5d49cad8a6d79e4ecefd06dc6e3db12
-      "XDG_DATA_DIRS=${glib.getSchemaDataDirPath gsettings-desktop-schemas}"
+      #
+      # The "Validate docs" test looks for various GIR dependencies, thus preserve the existing paths.
+      "XDG_DATA_DIRS=$XDG_DATA_DIRS:${glib.getSchemaDataDirPath gsettings-desktop-schemas}"
 
       # Tests need a cache directory
       "HOME=$TMPDIR"