diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4565c86..bc22ac6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,4 @@
-name: nim-secp256k1 CI
+name: CI
 on: [push, pull_request]
 
 jobs:
@@ -7,38 +7,18 @@ jobs:
       fail-fast: false
       max-parallel: 20
       matrix:
-        branch: [master]
+        test_lang: [c, cpp]
         target:
           - os: linux
             cpu: amd64
-            TEST_LANG: c
-          - os: linux
-            cpu: amd64
-            TEST_LANG: cpp
           - os: linux
             cpu: i386
-            TEST_LANG: c
-          - os: linux
-            cpu: i386
-            TEST_LANG: cpp
           - os: macos
             cpu: amd64
-            TEST_LANG: c
-          - os: macos
-            cpu: amd64
-            TEST_LANG: cpp
           - os: windows
             cpu: amd64
-            TEST_LANG: c
-          - os: windows
-            cpu: amd64
-            TEST_LANG: cpp
           - os: windows
             cpu: i386
-            TEST_LANG: c
-          - os: windows
-            cpu: i386
-            TEST_LANG: cpp
         include:
           - target:
               os: linux
@@ -50,7 +30,7 @@ jobs:
               os: windows
             builder: windows-2019
 
-    name: '${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ matrix.target.TEST_LANG }} (${{ matrix.branch }})'
+    name: '${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ matrix.test_lang }}'
     runs-on: ${{ matrix.builder }}
     steps:
       - name: Checkout nim-secp256k1
@@ -145,11 +125,10 @@ jobs:
         id: nim-cache
         uses: actions/cache@v2
         with:
-          path: nim
-          key: 'nim-${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ steps.versions.outputs.nimbus_build_system }}'
+          path: NimBinaries
+          key: 'NimBinaries-${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ steps.versions.outputs.nimbus_build_system }}'
 
       - name: Build Nim and associated tools
-        if: steps.nim-cache.outputs.cache-hit != 'true'
         shell: bash
         run: |
           curl -O -L -s -S https://raw.githubusercontent.com/status-im/nimbus-build-system/master/scripts/build_nim.sh
@@ -164,23 +143,11 @@ jobs:
             MAKE_CMD="make"
           fi
           env MAKE="$MAKE_CMD -j2" ARCH_OVERRIDE=$PLATFORM CC=gcc bash build_nim.sh nim csources dist/nimble NimBinaries
-
-          # clean up to save cache space
-          cd nim
-          rm koch
-          rm -rf nimcache
-          rm -rf csources
-          rm -rf tests
-          rm -rf dist
-          rm -rf .git
-
-      - name: Setup environment
-        shell: bash
-        run: echo '${{ github.workspace }}/nim/bin' >> $GITHUB_PATH
+          echo '${{ github.workspace }}/nim/bin' >> $GITHUB_PATH
 
       - name: Run nim-secp256k1 tests
         shell: bash
         working-directory: nim-secp256k1
         run: |
           nimble install -y --depsOnly
-          env TEST_LANG="${{ matrix.target.TEST_LANG }}" nimble test
+          env TEST_LANG="${{ matrix.test_lang }}" nimble test
diff --git a/README.md b/README.md
index b10a1ca..0fac3e2 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 [![License: Apache](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 ![Stability: experimental](https://img.shields.io/badge/stability-experimental-orange.svg)
-![Github action](https://github.com/status-im/nim-secp256k1/workflows/nim-secp256k1%20CI/badge.svg)
+![Github action](https://github.com/status-im/nim-secp256k1/workflows/CI/badge.svg)
 
 # Introduction
 
diff --git a/secp256k1.nimble b/secp256k1.nimble
index 8e821b6..ded90fa 100644
--- a/secp256k1.nimble
+++ b/secp256k1.nimble
@@ -11,18 +11,16 @@ requires "nim >= 1.2.0"
 requires "stew"
 requires "nimcrypto"
 
-proc getLang(): string =
-  result = "c"
+proc test(env, path: string) =
+  # Compilation language is controlled by TEST_LANG
+  var lang = "c"
   if existsEnv"TEST_LANG":
-    result = getEnv"TEST_LANG"
+    lang = getEnv"TEST_LANG"
 
-proc test(name: string, lang: string = "c") =
-  if not dirExists "build":
-    mkDir "build"
-  --run
-  --threads:on
-  switch("out", ("./build/" & name))
-  setCommand lang, "tests/" & name & ".nim"
+  exec "nim " & lang & " " & env &
+    " -r -f --hints:off --skipParentCfg " & path
 
 task test, "Tests":
-  test "all_tests", getLang()
+  test "--threads:on", "tests/all_tests"
+  test "--threads:off", "tests/all_tests"
+