diff --git a/source/dub/packagemanager.d b/source/dub/packagemanager.d
index f31f597..8d3dd12 100644
--- a/source/dub/packagemanager.d
+++ b/source/dub/packagemanager.d
@@ -15,6 +15,7 @@
 import dub.internal.logging;
 import dub.package_;
 import dub.recipe.io;
+import dub.recipe.selection;
 import dub.internal.configy.Exceptions;
 public import dub.internal.configy.Read : StrictMode;
 
@@ -1071,6 +1072,69 @@
 		return digest[].dup;
 	}
 
+	/**
+	 * Writes the selections file (`dub.selections.json`)
+	 *
+	 * The selections file is only used for the root package / project.
+	 * However, due to it being a filesystem interaction, it is managed
+	 * from the `PackageManager`.
+	 *
+	 * Params:
+	 *   project = The root package / project to read the selections file for.
+	 *   selections = The `SelectionsFile` to write.
+	 *   overwrite = Whether to overwrite an existing selections file.
+	 *               True by default.
+	 */
+	public void writeSelections(in Package project, in Selections!1 selections,
+		bool overwrite = true)
+	{
+		import dub.internal.vibecompat.core.file;
+
+		const path = project.path ~ "dub.selections.json";
+		if (!overwrite && existsFile(path))
+			return;
+		writeFile(path, selectionsToString(selections));
+	}
+
+	/// Package function to avoid code duplication with deprecated
+	/// SelectedVersions.save, merge with `writeSelections` in
+	/// the future.
+	package static string selectionsToString (in Selections!1 s)
+	{
+		Json json = selectionsToJSON(s);
+		assert(json.type == Json.Type.object);
+		assert(json.length == 2);
+		assert(json["versions"].type != Json.Type.undefined);
+
+		auto result = appender!string();
+		result.put("{\n\t\"fileVersion\": ");
+		result.writeJsonString(json["fileVersion"]);
+		result.put(",\n\t\"versions\": {");
+		auto vers = json["versions"].get!(Json[string]);
+		bool first = true;
+		foreach (k; vers.byKey.array.sort()) {
+			if (!first) result.put(",");
+			else first = false;
+			result.put("\n\t\t");
+			result.writeJsonString(Json(k));
+			result.put(": ");
+			result.writeJsonString(vers[k]);
+		}
+		result.put("\n\t}\n}\n");
+		return result.data;
+	}
+
+	/// Ditto
+	package static Json selectionsToJSON (in Selections!1 s)
+	{
+		Json serialized = Json.emptyObject;
+		serialized["fileVersion"] = s.fileVersion;
+		serialized["versions"] = Json.emptyObject;
+		foreach (p, dep; s.versions)
+			serialized["versions"][p] = dep.toJson(true);
+		return serialized;
+	}
+
 	/// Adds the package and scans for sub-packages.
 	protected void addPackages(ref Package[] dst_repos, Package pack)
 	{
diff --git a/source/dub/project.d b/source/dub/project.d
index f28c337..0f4ce82 100644
--- a/source/dub/project.d
+++ b/source/dub/project.d
@@ -1340,10 +1340,9 @@
 		const name = PackageName(m_rootPackage.basePackage.name);
 		if (m_selections.hasSelectedVersion(name))
 			m_selections.deselectVersion(name);
-
-		auto path = m_rootPackage.path ~ SelectedVersions.defaultFile;
-		if (m_selections.dirty || !existsFile(path))
-			m_selections.save(path);
+		this.m_packageManager.writeSelections(
+			this.m_rootPackage, this.m_selections.m_selections,
+			this.m_selections.dirty);
 	}
 
 	deprecated bool isUpgradeCacheUpToDate()
@@ -1967,30 +1966,10 @@
 		should be used as the file name and the directory should be the root
 		directory of the project's root package.
 	*/
+	deprecated("Use `PackageManager.writeSelections` to write a `SelectionsFile`")
 	void save(NativePath path)
 	{
-		Json json = serialize();
-		auto result = appender!string();
-
-		assert(json.type == Json.Type.object);
-		assert(json.length == 2);
-		assert(json["versions"].type != Json.Type.undefined);
-
-		result.put("{\n\t\"fileVersion\": ");
-		result.writeJsonString(json["fileVersion"]);
-		result.put(",\n\t\"versions\": {");
-		auto vers = json["versions"].get!(Json[string]);
-		bool first = true;
-		foreach (k; vers.byKey.array.sort()) {
-			if (!first) result.put(",");
-			else first = false;
-			result.put("\n\t\t");
-			result.writeJsonString(Json(k));
-			result.put(": ");
-			result.writeJsonString(vers[k]);
-		}
-		result.put("\n\t}\n}\n");
-		path.writeFile(result.data);
+		path.writeFile(PackageManager.selectionsToString(this.m_selections));
 		m_dirty = false;
 		m_bare = false;
 	}
@@ -2014,14 +1993,9 @@
 		else throw new Exception(format("Unexpected type for dependency: %s", j));
 	}
 
-	Json serialize()
-	const {
-		Json serialized = Json.emptyObject;
-		serialized["fileVersion"] = m_selections.fileVersion;
-		serialized["versions"] = Json.emptyObject;
-		foreach (p, dep; m_selections.versions)
-			serialized["versions"][p] = dep.toJson(true);
-		return serialized;
+	deprecated("JSON serialization is deprecated")
+	Json serialize() const {
+		return PackageManager.selectionsToJSON(this.m_selections);
 	}
 
 	deprecated("JSON deserialization is deprecated")
diff --git a/source/dub/test/base.d b/source/dub/test/base.d
index 3c7f173..e05d9ae 100644
--- a/source/dub/test/base.d
+++ b/source/dub/test/base.d
@@ -65,6 +65,7 @@
 import dub.packagesuppliers.packagesupplier;
 import dub.project;
 import dub.recipe.io : parsePackageRecipe;
+import dub.recipe.selection;
 
 /// Example of a simple unittest for a project with a single dependency
 unittest
@@ -219,7 +220,7 @@
 	/// Loads a specific package as the main project package (can be a sub package)
 	public override void loadPackage(Package pack)
 	{
-		m_project = new Project(m_packageManager, pack, new TestSelectedVersions());
+		m_project = new Project(m_packageManager, pack, new SelectedVersions());
 	}
 
 	/// Reintroduce parent overloads
@@ -238,31 +239,6 @@
 }
 
 /**
- *
- */
-public class TestSelectedVersions : SelectedVersions {
-	import dub.recipe.selection;
-
-	/// Forward to parent's constructor
-	public this(uint version_ = FileVersion) @safe pure
-	{
-		super(version_);
-	}
-
-	/// Ditto
-	public this(Selections!1 data) @safe pure nothrow @nogc
-	{
-		super(data);
-	}
-
-	/// Do not do IO
-	public override void save(NativePath path)
-	{
-		// No-op
-	}
-}
-
-/**
  * A `PackageManager` suitable to be used in unittests
  *
  * This `PackageManager` does not perform any IO. It imitates the base
@@ -400,6 +376,16 @@
         return false;
 	}
 
+    /// Save the `dub.selections.json` to the vfs
+    public override void writeSelections(in Package project,
+        in Selections!1 selections, bool overwrite = true)
+    {
+        const path = project.path ~ "dub.selections.json";
+        if (!overwrite && this.fs.existsFile(path))
+            return;
+        this.fs.writeFile(path, selectionsToString(selections));
+    }
+
     /// Add a reachable SCM package to this `PackageManager`
     public void addTestSCMPackage(in Repository repo, string dub_json)
     {