diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d9b33da..84c6df1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,13 @@ jobs:
         run: nimble setup -y
 
       - name: Unit tests
-        run: nimble test
+        # same reason as integration tests: nimble exits with code 0 even on failure.
+        run: |
+          cmake -B vendor/libplum/build -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=OFF vendor/libplum
+          cmake --build vendor/libplum/build
+          cp vendor/libplum/build/libplum.a vendor/libplum/libplum.a
+          nim c -o:tests/test_plum tests/test_plum.nim
+          ./tests/test_plum
 
       - name: Integration tests
         # we call docker directly instead of nimble testIntegration because nimble