diff --git a/source/dub/recipe/packagerecipe.d b/source/dub/recipe/packagerecipe.d
index 5573018..20926ee 100644
--- a/source/dub/recipe/packagerecipe.d
+++ b/source/dub/recipe/packagerecipe.d
@@ -32,11 +32,18 @@
 	example, "packa:packb:packc" references a package named "packc" that is a
 	sub package of "packb", which in turn is a sub package of "packa".
 */
+deprecated("This function is not supported as subpackages cannot be nested")
 string[] getSubPackagePath(string package_name) @safe pure
 {
 	return package_name.split(":");
 }
 
+deprecated @safe unittest
+{
+	assert(getSubPackagePath("packa:packb:packc") == ["packa", "packb", "packc"]);
+	assert(getSubPackagePath("pack") == ["pack"]);
+}
+
 /**
 	Returns the name of the top level package for a given (sub) package name of
 	format `"basePackageName"` or `"basePackageName:subPackageName"`.
@@ -62,8 +69,6 @@
 
 @safe unittest
 {
-	assert(getSubPackagePath("packa:packb:packc") == ["packa", "packb", "packc"]);
-	assert(getSubPackagePath("pack") == ["pack"]);
 	assert(getBasePackageName("packa:packb:packc") == "packa");
 	assert(getBasePackageName("pack") == "pack");
 	assert(getSubPackageName("packa:packb:packc") == "packb:packc");