diff --git a/.github/workflows/github-workflow-tests.lisp b/.github/workflows/github-workflow-tests.lisp
new file mode 100644
index 0000000..375746f
--- /dev/null
+++ b/.github/workflows/github-workflow-tests.lisp
@@ -0,0 +1,23 @@
+(in-package :cl-user)
+
+#+sbcl
+(require :asdf)
+
+(load "/tmp/ql-dir/quicklisp.lisp")
+(quicklisp-quickstart:install)
+
+(ql:quickload :closer-mop)
+(ql:quickload :yacc)
+(ql:quickload :cl-custom-hash-table)
+
+#+(or abcl clisp ecl)
+(ql:quickload :cl-fad)
+
+#-allegro
+(ql:quickload :ptester)
+
+(load "/home/runner/work/cl-python/cl-python/clpython.asd")
+
+(ql:quickload :clpython)
+
+(asdf:test-system :clpython)
diff --git a/.github/workflows/run-tests.yaml b/.github/workflows/run-tests.yaml
new file mode 100644
index 0000000..5b316d2
--- /dev/null
+++ b/.github/workflows/run-tests.yaml
@@ -0,0 +1,43 @@
+name: build & test
+on:
+  push:
+    branches:
+     - master
+     - dev
+jobs:
+
+  install_quicklisp:
+    name: Install QuickLisp
+    runs-on: ubuntu-latest
+    steps:
+     - run: |
+          cd /tmp
+          mkdir ql-dir
+          cd ql-dir
+          wget -q https://beta.quicklisp.org/quicklisp.lisp
+          chmod -R a+rwx /tmp/ql-dir
+     - name: Upload Quicklisp artifact
+       uses: actions/upload-artifact@v4
+       with:
+          name: ql-artifact
+          path: /tmp/ql-dir
+
+  run_test_suites:
+    name: Test on ${{ matrix.scenario }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        scenario: [sbcl]
+    needs: [install_quicklisp]
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/download-artifact@v4
+        with:
+          name: ql-artifact
+          path: /tmp/ql-dir
+
+      - if: matrix.scenario == 'sbcl'
+        run: |
+         sudo apt-get install sbcl
+         sbcl --script /home/runner/work/cl-python/cl-python/.github/workflows/github-workflow-tests.lisp
diff --git a/clpython.asd b/clpython.asd
index d0aa9e0..b58f8c7 100644
--- a/clpython.asd
+++ b/clpython.asd
@@ -12,6 +12,8 @@
 (eval-when (:compile-toplevel)
   (error "This ASDF file should be run interpreted."))
 
+(eval-when (compile load eval)
+  (import '(asdf:defsystem asdf:load-op asdf:test-op)))
 
 ;;; CL-Python is split into several ASDF systems, to make it possible to load
 ;;; specific components -- in particular, to load the compiler or parser without
@@ -31,7 +33,7 @@
                                        (muffle-warning c))))))
     (funcall thunk)))
 
-(defsystem "clpython/basic"
+(asdf:defsystem "clpython/basic"
     :description "CLPython package and utils"
     :depends-on ("closer-mop")
     :serial t
@@ -53,7 +55,7 @@
 (when (asdf:find-system "yacc" nil)
   (pushnew :have-cl-yacc *features*))
 
-(defsystem "clpython/parser"
+(asdf:defsystem "clpython/parser"
     :description "Python parser, code walker, and pretty printer"
     :depends-on ("clpython/basic"
                  "closer-mop"
@@ -68,7 +70,7 @@
                                        (:file "walk"   )
                                        (:file "pprint" )))))
 
-(defsystem "clpython/compiler"
+(asdf:defsystem "clpython/compiler"
     :description "Python compiler"
     :depends-on ("clpython/basic" "clpython/parser" "clpython/runtime" "closer-mop")
     :serial t
@@ -81,7 +83,7 @@
                                        (:file "generator"    )
                                        (:file "optimize"     )))))
 
-(defsystem "clpython/runtime"
+(asdf:defsystem "clpython/runtime"
     :description "Python runtime environment"
     :depends-on ("clpython/basic" "closer-mop" #+(or abcl clisp ecl) "cl-custom-hash-table" "cl-fad")
     :components ((:module "runtime"
@@ -96,7 +98,7 @@
                                        (:file "run"          )
                                        (:file "import"       )))))
 
-(defsystem "clpython/lib"
+(asdf:defsystem "clpython/lib"
     :description "Python module library"
     :depends-on ("clpython/basic" "clpython/runtime" "clpython/compiler" #| TODO: remove compiler dep |#)
     :components ((:module "lib"
@@ -141,7 +143,7 @@
                                        (:file "time" :depends-on ("lsetup"))
                                        (:file "_weakref" :depends-on ("lsetup"))))))
 
-(defsystem "clpython/contrib"
+(asdf:defsystem "clpython/contrib"
     :description "CLPython contributions and experiments"
     :depends-on ("clpython/basic" "clpython/runtime" "clpython/compiler")
     :components ((:module "contrib"