diff --git a/source/dub/dependency.d b/source/dub/dependency.d
index 2397f67..a06fbc3 100644
--- a/source/dub/dependency.d
+++ b/source/dub/dependency.d
@@ -584,7 +584,7 @@
 	CONFIG[string] resolve(TreeNode root)
 	{
 		static string rootPackage(string p) {
-			auto idx = p.indexOf(":");
+			auto idx = std.string.indexOf(p, ":");
 			if (idx < 0) return p;
 			return p[0 .. idx];
 		}