diff --git a/.github/workflows/exercises.yml b/.github/workflows/exercises.yml
index 83013cae..f8f4c012 100644
--- a/.github/workflows/exercises.yml
+++ b/.github/workflows/exercises.yml
@@ -23,7 +23,7 @@ jobs:
             os: linux
 
     name: nim-${{ matrix.nim }}-${{ matrix.os }}
-    runs-on: ${{ matrix.os == 'linux' && 'ubuntu-24.04' || (matrix.os == 'macOS' && 'macos-13' || 'windows-2022') }}
+    runs-on: ${{ (matrix.os == 'linux' && 'ubuntu-24.04') || (matrix.os == 'macOS' && 'macos-13') || (matrix.os == 'macOS' && 'macos-15') || 'windows-2022' }}
 
     steps:
       - name: Checkout exercism/nim