diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 64a0b0f7..4867d459 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,6 +8,9 @@ on:
   pull_request:
     branches:
       - main
+  pull_request_target:
+    branches:
+      - main
   merge_group:
     branches:
       - main
@@ -27,6 +30,8 @@ jobs:
         uses: actions/checkout@v4
         with:
           submodules: recursive
+          ref: ${{ github.event.pull_request.head.sha }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
 
       - name: Setup
         uses: ./.github/actions/setup
@@ -46,6 +51,9 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
       
       - name: Setup
         uses: ./.github/actions/setup
@@ -67,6 +75,9 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
       
       - name: Setup
         uses: ./.github/actions/setup
diff --git a/orchestrator/fork.go b/orchestrator/fork.go
index 13f31920..7149acc9 100644
--- a/orchestrator/fork.go
+++ b/orchestrator/fork.go
@@ -23,7 +23,7 @@ func NetworkConfigFromForkCLIConfig(log log.Logger, envPrefix string, forkConfig
 
 	// L1
 	l1RpcUrl := superchain.Config.L1.PublicRPC
-	if url, ok := os.LookupEnv(fmt.Sprintf("%s_RPC_URL_%s", envPrefix, strings.ToUpper(forkConfig.Network))); ok {
+	if url, ok := os.LookupEnv(fmt.Sprintf("%s_RPC_URL_%s", envPrefix, strings.ToUpper(forkConfig.Network))); ok && url != "" {
 		log.Info("detected rpc override", "name", forkConfig.Network)
 		l1RpcUrl = url
 	}
@@ -68,7 +68,7 @@ func NetworkConfigFromForkCLIConfig(log log.Logger, envPrefix string, forkConfig
 		}
 
 		l2RpcUrl := chainCfg.PublicRPC
-		if url, ok := os.LookupEnv(fmt.Sprintf("%s_RPC_URL_%s", envPrefix, strings.ToUpper(chainCfg.Chain))); ok {
+		if url, ok := os.LookupEnv(fmt.Sprintf("%s_RPC_URL_%s", envPrefix, strings.ToUpper(chainCfg.Chain))); ok && url != "" {
 			log.Info("detected rpc override", "name", chainCfg.Chain)
 			l2RpcUrl = url
 		}