diff --git a/README.md b/README.md
index 7848551..3a65ddd 100644
--- a/README.md
+++ b/README.md
@@ -56,7 +56,7 @@ jobs:
 ```
 
 By default, the action will evaluate `using Package` where `Package` is the name of the julia repo that the action runs on.
-A custom script can be provided by passing `test_script`. Note that both runs should be given the same script
+A custom script can be provided by passing `test_script`. If it is necessary to setup alter the environment the code is run in, you can pass a `setup_script` with the necessary Pkg operations. Note that both runs should be given the same script
 
 i.e.
 ```yaml
@@ -64,4 +64,5 @@ i.e.
   id: invs_pr
   with:
     test_script: 'using Package; Package.foo(1)'
+    setup_script: 'using Pkg; Pkg.develop(["Foo", "Bar"])'
 ```
diff --git a/action.yml b/action.yml
index 907306c..ff13feb 100644
--- a/action.yml
+++ b/action.yml
@@ -30,14 +30,21 @@ runs:
             TESTSCRIPT=${{ inputs.test_script }}
           fi
           echo "testscript=$TESTSCRIPT" >> $GITHUB_OUTPUT
+          if [[ '${{ inputs.setup_script }}' == '' ]]; then
+            SETUPSCRIPT="using Pkg;Pkg.develop(\"${PACKAGENAME}\")"
+          else
+            SETUPSCRIPT=${{ inputs.setup_script }}
+          fi
+          echo "setupscript=$SETUPSCRIPT" >> $GITHUB_OUTPUT
       shell: bash
       
     - name: Install SnoopCompile tools
-      run: julia --project -e 'using Pkg; Pkg.add(["SnoopCompileCore", "SnoopCompile", "PrettyTables"])'
+      run: julia 'using Pkg; Pkg.add(["SnoopCompileCore", "SnoopCompile", "PrettyTables"])'
       shell: bash
     - name: Load package on branch
       id: invs
       run: |
+        ${{ steps.info.outputs.setupscript }}
         using SnoopCompileCore
         invalidations = @snoopr begin ${{ steps.info.outputs.testscript }} end
         
@@ -61,4 +68,4 @@ runs:
           println(io, "total=$(inv_total)")
           println(io, "deps=$(inv_deps)")
         end
-      shell: julia --color=yes --project=. {0}    
+      shell: julia --color=yes {0}