diff --git a/vlib/v/ast/table.v b/vlib/v/ast/table.v
index 2ef862e65c..097ceacb3a 100644
--- a/vlib/v/ast/table.v
+++ b/vlib/v/ast/table.v
@@ -1799,7 +1799,12 @@ pub fn (mut t Table) generic_type_names(generic_type Type) []string {
 		}
 		Struct, Interface, SumType {
 			if sym.info.is_generic {
-				names << sym.info.generic_types.map(t.sym(it).name)
+				if sym.generic_types.len > 0 {
+					// Foo[U] (declaration: Foo[T])
+					names << sym.generic_types.map(t.sym(it).name)
+				} else {
+					names << sym.info.generic_types.map(t.sym(it).name)
+				}
 			}
 		}
 		else {}
diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 24d6917fee..c86af5079f 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -131,10 +131,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 			c.error('fixed array cannot be returned by function', node.return_type_pos)
 		}
 		// Ensure each generic type of the parameter was declared in the function's definition
-		// TODO: fix inconsistent return_type type case
-		if node.return_type.has_flag(.generic) && (return_sym.kind == .any
-			|| (return_sym.kind == .array
-			&& c.table.sym((return_sym.info as ast.Array).elem_type).kind == .any)) {
+		if node.return_type.has_flag(.generic) {
 			generic_names := c.table.generic_type_names(node.return_type)
 			for name in generic_names {
 				if name !in node.generic_names {