diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4f5fbe6..04b3d79 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -5,6 +5,7 @@ on:
   pull_request:
   schedule:
     - cron: '0 0 * * 5'
+  workflow_dispatch:
 
 jobs:
 
@@ -54,10 +55,11 @@ jobs:
   VUnit:
     needs: [build]
     runs-on: ubuntu-latest
-    container: ghdl/vunit:llvm
     steps:
     - uses: actions/checkout@v2
-    - run: python3 ./run.py -p10
+    - uses: docker://ghdl/vunit:llvm
+      with:
+        args: python3 ./run.py -p10
 
   symbiflow:
     strategy:
diff --git a/run.py b/run.py
index 2ffbc9e..3bf49da 100644
--- a/run.py
+++ b/run.py
@@ -1,29 +1,23 @@
 from pathlib import Path
 from vunit import VUnit
-from glob import glob
 
-prj = VUnit.from_argv()
-prj.add_osvvm()
-root = Path(__file__).parent
+ROOT = Path(__file__).parent
 
-lib = prj.add_library("lib")
-lib.add_source_files(root / "litedram" / "extras" / "*.vhdl")
-lib.add_source_files(root / "litedram" / "generated" / "sim" / "*.vhdl")
+PRJ = VUnit.from_argv()
+PRJ.add_osvvm()
 
-# Use multiply.vhd and not xilinx-mult.vhd. Use VHDL-based random.
-vhdl_files = glob(str(root / "*.vhdl"))
-vhdl_files = [
+PRJ.add_library("lib").add_source_files([
+    ROOT / "litedram" / "extras" / "*.vhdl",
+    ROOT / "litedram" / "generated" / "sim" / "*.vhdl"
+] + [
     src_file
-    for src_file in vhdl_files
-    if ("xilinx-mult" not in src_file)
-    and ("foreign_random" not in src_file)
-    and ("nonrandom" not in src_file)
-]
-lib.add_source_files(vhdl_files)
+    for src_file in ROOT.glob("*.vhdl")
+    # Use multiply.vhd and not xilinx-mult.vhd. Use VHDL-based random.
+    if not any(exclude in str(src_file) for exclude in ["xilinx-mult", "foreign_random", "nonrandom"])
+])
 
-unisim = prj.add_library("unisim")
-unisim.add_source_files(root / "sim-unisim" / "*.vhdl")
+PRJ.add_library("unisim").add_source_files(ROOT / "sim-unisim" / "*.vhdl")
 
-prj.set_sim_option("disable_ieee_warnings", True)
+PRJ.set_sim_option("disable_ieee_warnings", True)
 
-prj.main()
+PRJ.main()