diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f70b677ac0c..46627105cc7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -70,6 +70,14 @@ jobs:
         with:
           global-json-file: global.json
 
+      - name: Override NuGet packages
+        shell: bash
+        run: |
+          dotnet pack -c Release crates/bindings-csharp/BSATN.Runtime
+          dotnet pack -c Release crates/bindings-csharp/Runtime
+          cd sdks/csharp
+          ./tools~/write-nuget-config.sh ../..
+
       # nodejs and pnpm are required for the typescript quickstart smoketest
       - name: Set up Node.js
         uses: actions/setup-node@v4
@@ -571,6 +579,10 @@ jobs:
           cd sdks/csharp
           ./tools~/write-nuget-config.sh ../..
 
+      - name: Restore .NET solution
+        working-directory: sdks/csharp
+        run: dotnet restore --configfile NuGet.Config SpacetimeDB.ClientSDK.sln
+
       # Now, setup the Unity tests.
       - name: Patch spacetimedb dependency in Cargo.toml
         working-directory: demo/Blackholio/server-rust
@@ -693,9 +705,13 @@ jobs:
           cd sdks/csharp
           ./tools~/write-nuget-config.sh ../..
 
+      - name: Restore .NET solution
+        working-directory: sdks/csharp
+        run: dotnet restore --configfile NuGet.Config SpacetimeDB.ClientSDK.sln
+
       - name: Run .NET tests
         working-directory: sdks/csharp
-        run: dotnet test -warnaserror
+        run: dotnet test -warnaserror --no-restore
 
       - name: Verify C# formatting
         working-directory: sdks/csharp
diff --git a/sdks/csharp/tools~/write-nuget-config.sh b/sdks/csharp/tools~/write-nuget-config.sh
index 7849ed08a96..aabae5a19e3 100755
--- a/sdks/csharp/tools~/write-nuget-config.sh
+++ b/sdks/csharp/tools~/write-nuget-config.sh
@@ -10,14 +10,16 @@ cd ..
 # available.
 # See https://learn.microsoft.com/en-us/nuget/reference/nuget-config-file for more info on the config file,
 # and https://tldp.org/LDP/abs/html/here-docs.html for more info on this bash feature.
-cat >nuget.config <<EOF
+cat >NuGet.Config <<EOF
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <packageSources>
+    <clear />
     <!-- Local NuGet repositories -->
     <add key="Local SpacetimeDB.BSATN.Runtime" value="${SPACETIMEDB_REPO_PATH}/crates/bindings-csharp/BSATN.Runtime/bin/Release" />
     <!-- We need to override the module runtime as well because the examples use it -->
     <add key="Local SpacetimeDB.Runtime" value="${SPACETIMEDB_REPO_PATH}/crates/bindings-csharp/Runtime/bin/Release" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
   <packageSourceMapping>
     <!-- Ensure that SpacetimeDB.BSATN.Runtime is used from the local folder. -->
@@ -36,5 +38,33 @@ cat >nuget.config <<EOF
 </configuration>
 EOF
 
-echo "Wrote nuget.config contents:"
-cat nuget.config
+cat >"${SPACETIMEDB_REPO_PATH}/NuGet.Config" <<EOF
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <!-- Local NuGet repositories -->
+    <add key="Local SpacetimeDB.BSATN.Runtime" value="crates/bindings-csharp/BSATN.Runtime/bin/Release" />
+    <!-- We need to override the module runtime as well because the examples use it -->
+    <add key="Local SpacetimeDB.Runtime" value="crates/bindings-csharp/Runtime/bin/Release" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+  <packageSourceMapping>
+    <!-- Ensure that SpacetimeDB.BSATN.Runtime is used from the local folder. -->
+    <!-- Otherwise we risk an outdated version being quietly pulled from NuGet for testing. -->
+    <packageSource key="Local SpacetimeDB.BSATN.Runtime">
+      <package pattern="SpacetimeDB.BSATN.Runtime" />
+    </packageSource>
+    <packageSource key="Local SpacetimeDB.Runtime">
+      <package pattern="SpacetimeDB.Runtime" />
+    </packageSource>
+    <!-- Fallback for other packages (e.g. test deps). -->
+    <packageSource key="nuget.org">
+      <package pattern="*" />
+    </packageSource>
+  </packageSourceMapping>
+</configuration>
+EOF
+
+echo "Wrote sdks/csharp/NuGet.Config contents:"
+cat NuGet.Config
diff --git a/smoketests/tests/quickstart.py b/smoketests/tests/quickstart.py
index 254db8bed04..18696caae0c 100644
--- a/smoketests/tests/quickstart.py
+++ b/smoketests/tests/quickstart.py
@@ -57,6 +57,18 @@ def load_nuget_config(p: Path):
             return xmltodict.parse(f.read(), force_list=["add", "packageSource", "package"])
     return {}
 
+
+def _nuget_config_path(project_dir: Path) -> Path:
+    p_upper = project_dir / "NuGet.Config"
+    if p_upper.exists():
+        return p_upper
+
+    p_lower = project_dir / "nuget.config"
+    if p_lower.exists():
+        return p_lower
+
+    return p_upper
+
 def save_nuget_config(p: Path, doc: dict):
     # Write back (pretty, UTF-8, no BOM)
     xml = xmltodict.unparse(doc, pretty=True)
@@ -66,8 +78,8 @@ def add_source(doc: dict, *, key: str, path: str) -> None:
     cfg = doc.setdefault("configuration", {})
     sources = cfg.setdefault("packageSources", {})
     source_entries = sources.setdefault("add", [])
-    source = {"@key": key, "@value": path}
-    source_entries.append(source)
+
+    source_entries.append({"@key": key, "@value": str(path)})
 
 def add_mapping(doc: dict, *, key: str, pattern: str) -> None:
     cfg = doc.setdefault("configuration", {})
@@ -90,12 +102,25 @@ def add_mapping(doc: dict, *, key: str, pattern: str) -> None:
 def override_nuget_package(*, project_dir: Path, package: str, source_dir: Path, build_subdir: str):
     """Override nuget config to use a local NuGet package on a .NET project"""
     # Make sure the local package is built
-    run_cmd("dotnet", "pack", cwd=source_dir)
+    repo_nuget_config = STDB_DIR / "NuGet.Config"
+    if repo_nuget_config.exists():
+        run_cmd(
+            "dotnet",
+            "restore",
+            "--configfile",
+            str(repo_nuget_config),
+            cwd=source_dir,
+            capture_stderr=True,
+        )
+        run_cmd("dotnet", "pack", "-c", "Release", "--no-restore", cwd=source_dir)
+    else:
+        run_cmd("dotnet", "pack", "-c", "Release", cwd=source_dir)
 
-    p = Path(project_dir) / "nuget.config"
+    p = _nuget_config_path(Path(project_dir))
     doc = load_nuget_config(p)
     add_source(doc, key=package, path=source_dir/build_subdir)
     add_mapping(doc, key=package, pattern=package)
+    add_source(doc, key="nuget.org", path="https://api.nuget.org/v3/index.json")
     # Fallback for other packages
     add_mapping(doc, key="nuget.org", pattern="*")
     save_nuget_config(p, doc)