diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 53f53a8..04d73b9 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -19,6 +19,7 @@ jobs:
       matrix:
         version:
           - '1.8'
+          - '1'
           - 'nightly'
         os:
           - ubuntu-latest
@@ -33,3 +34,10 @@ jobs:
       - uses: julia-actions/cache@v1
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v4
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: lcov.info
+          fail_ci_if_error: false
+        
diff --git a/README.md b/README.md
index 94baee1..22f3c59 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 # HerbCore.jl
 
+[![codecov](https://codecov.io/github/Herb-AI/HerbCore.jl/graph/badge.svg?token=92CPVT1ZQU)](https://codecov.io/github/Herb-AI/HerbCore.jl)
 [![Build Status](https://github.com/Herb-AI/HerbCore.jl/actions/workflows/CI.yml/badge.svg?branch=master)](https://github.com/Herb-AI/HerbCore.jl/actions/workflows/CI.yml?query=branch%3Amaster)
 
 This package provides the core functionality of the program synthesis library `Herb.jl` to avoid circular dependencies for core principles. Used for representing and manipulating expression trees, and abstract types for constraints and grammars.