diff --git a/spec/compiler/semantic/alias_spec.cr b/spec/compiler/semantic/alias_spec.cr
index 4005bfd61606..eecd1e22034c 100644
--- a/spec/compiler/semantic/alias_spec.cr
+++ b/spec/compiler/semantic/alias_spec.cr
@@ -297,4 +297,17 @@ describe "Semantic: alias" do
       ),
       "undefined constant T"
   end
+
+  it "doesn't crash by infinite recursion against type alias and generics (#5329)" do
+    assert_error %(
+      class Foo(T)
+        def initialize(@foo : T)
+        end
+      end
+
+      alias Bar = Foo(Bar | Int32)
+
+      Foo(Bar).new(Foo.new(1).as(Bar))
+    ), "can't cast Foo(Int32) to Bar"
+  end
 end
diff --git a/src/compiler/crystal/semantic/restrictions.cr b/src/compiler/crystal/semantic/restrictions.cr
index 6ad1b6d19f44..99ecb1e3f2cd 100644
--- a/src/compiler/crystal/semantic/restrictions.cr
+++ b/src/compiler/crystal/semantic/restrictions.cr
@@ -667,7 +667,10 @@ module Crystal
       elsif context.strict?
         type_var == other_type_var
       else
-        type_var.restrict(other_type_var, context) == type_var
+        # To prevent infinite recursion, it checks equality between
+        # `type_var` and `other_type_var` directly before try to restrict
+        # `type_var` by `other_type_var`.
+        type_var == other_type_var || type_var.restrict(other_type_var, context) == type_var
       end
     end
   end