diff --git a/testbed/3004.misc.rst b/testbed/3004.misc.rst
new file mode 100644
index 0000000000..282fb818aa
--- /dev/null
+++ b/testbed/3004.misc.rst
@@ -0,0 +1 @@
+Toga's testbed Briefcase project now builds with and tests against prerelease versions of dependencies.
diff --git a/testbed/pyproject.toml b/testbed/pyproject.toml
index 05b94b9715..123c8ca319 100644
--- a/testbed/pyproject.toml
+++ b/testbed/pyproject.toml
@@ -34,6 +34,9 @@ test_sources = [
     "tests",
 ]
 requires = [
+    # install prerelease versions of Toga's dependencies.
+    # this can catch issues with upcoming releases before final release.
+    "--pre",
     "../core",
 ]