diff --git a/repos/gems/src/server/terminal/main.cc b/repos/gems/src/server/terminal/main.cc
index fbacec3b4..870a2a182 100644
--- a/repos/gems/src/server/terminal/main.cc
+++ b/repos/gems/src/server/terminal/main.cc
@@ -368,7 +368,7 @@ void Terminal::Main::_handle_input()
 
 			if (special_sequence)
 				_read_buffer.add(special_sequence);
-			else
+			else if (codepoint.valid())
 				_read_buffer.add(codepoint);
 		});
 	});
diff --git a/repos/os/include/util/utf8.h b/repos/os/include/util/utf8.h
index 8bf229def..0caa452ec 100644
--- a/repos/os/include/util/utf8.h
+++ b/repos/os/include/util/utf8.h
@@ -25,7 +25,7 @@ namespace Genode {
 
 struct Genode::Codepoint
 {
-	static constexpr uint32_t INVALID = 0xfffd;
+	static constexpr uint32_t INVALID = 0xfffe;
 
 	uint32_t value;
 
diff --git a/repos/os/src/test/utf8/main.cc b/repos/os/src/test/utf8/main.cc
index cb47385b3..57ec2551c 100644
--- a/repos/os/src/test/utf8/main.cc
+++ b/repos/os/src/test/utf8/main.cc
@@ -107,7 +107,7 @@ void Component::construct(Genode::Env &env)
 	              Expect_codepoint(0x3b5));
 
 	/* 2.1.1  1 byte  (U-00000000) */
-	test("�", Expect_invalid(), Expect_end());
+	test("\x00", Expect_codepoint(0x00), Expect_end());
 
 	/* 2.1.2  2 bytes (U-00000080) */
 	test("\xc2\x80", Expect_codepoint(0x80), Expect_end());