diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 72952f0..3c13bd7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -10,7 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         cache_nonce: [ 1 ]
-        nim_version: [ 1.2.18, 1.4.8, 1.6.4 ]
+        nim_version: [ 1.2.18, 1.4.8, 1.6.6 ]
         platform:
           - {
             icon: 🐧,
@@ -139,9 +139,16 @@ jobs:
           if [[ ${{ matrix.platform.os }} = macos ]]; then
             export PATH="$(brew --prefix)/opt/llvm/bin:${PATH}"
             export LDFLAGS="-L$(brew --prefix)/opt/libomp/lib -L$(brew --prefix)/opt/llvm/lib -Wl,-rpath,$(brew --prefix)/opt/llvm/lib"
-            nimble test -d:verbose -d:release -d:LeopardCmakeFlags="-DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=$(brew --prefix)/opt/llvm/bin/clang -DCMAKE_CXX_COMPILER=$(brew --prefix)/opt/llvm/bin/clang++" -d:LeopardExtraCompilerlags="-fopenmp" -d:LeopardExtraLinkerFlags="-fopenmp -L$(brew --prefix)/opt/libomp/lib"
+            compiler_extra_options="-d:LeopardCmakeFlags='-DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=$(brew --prefix)/opt/llvm/bin/clang -DCMAKE_CXX_COMPILER=$(brew --prefix)/opt/llvm/bin/clang++' -d:LeopardExtraCompilerlags='-fopenmp' -d:LeopardExtraLinkerFlags='-fopenmp -L$(brew --prefix)/opt/libomp/lib'"
+          fi
+          if [[ ${{ matrix.nim_version }} = 1.2.* ]]; then
+            eval nimble --verbose test -d:release --gc:refc ${compiler_extra_options}
+          elif [[ ${{ matrix.nim_version }} = 1.4.* ]]; then
+            eval nimble --verbose test -d:release --gc:refc ${compiler_extra_options}
+            eval nimble --verbose test -d:release --gc:orc ${compiler_extra_options}
           else
-            nimble test -d:verbose -d:release
+            eval nimble --verbose test -d:release --mm:refc ${compiler_extra_options}
+            eval nimble --verbose test -d:release --mm:orc ${compiler_extra_options}
           fi
           if [[ ${{ matrix.platform.os }} = macos ]]; then
             echo