diff --git a/cms/db/contest.py b/cms/db/contest.py
index 7543c58d6..2789e952b 100644
--- a/cms/db/contest.py
+++ b/cms/db/contest.py
@@ -79,7 +79,7 @@ class Contest(Base):
     languages = Column(
         ARRAY(String),
         nullable=False,
-        default=["C11 / gcc", "C++17 / g++", "Pascal / fpc"])
+        default=["C11 / gcc", "C++20 / g++", "Pascal / fpc"])
 
     # Whether contestants allowed to download their submissions.
     submissions_download_allowed = Column(
diff --git a/cms/grading/languages/cpp20_gpp.py b/cms/grading/languages/cpp20_gpp.py
new file mode 100644
index 000000000..3d70ce27f
--- /dev/null
+++ b/cms/grading/languages/cpp20_gpp.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+
+# Contest Management System - http://cms-dev.github.io/
+# Copyright © 2024 Filippo Casarin <casarin.filippo17@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""C++20 programming language definition."""
+
+from cms.grading import CompiledLanguage
+
+
+__all__ = ["Cpp20Gpp"]
+
+
+class Cpp20Gpp(CompiledLanguage):
+    """This defines the C++ programming language, compiled with g++ (the
+    version available on the system) using the C++20 standard.
+
+    """
+
+    @property
+    def name(self):
+        """See Language.name."""
+        return "C++20 / g++"
+
+    @property
+    def source_extensions(self):
+        """See Language.source_extensions."""
+        return [".cpp", ".cc", ".cxx", ".c++", ".C"]
+
+    @property
+    def header_extensions(self):
+        """See Language.header_extensions."""
+        return [".h"]
+
+    @property
+    def object_extensions(self):
+        """See Language.object_extensions."""
+        return [".o"]
+
+    def get_compilation_commands(self,
+                                 source_filenames, executable_filename,
+                                 for_evaluation=True):
+        """See Language.get_compilation_commands."""
+        command = ["/usr/bin/g++"]
+        if for_evaluation:
+            command += ["-DEVAL"]
+        command += ["-std=gnu++20", "-O2", "-pipe", "-static",
+                    "-s", "-o", executable_filename]
+        command += source_filenames
+        return [command]
diff --git a/cmstestsuite/Tests.py b/cmstestsuite/Tests.py
index 2cf440d4a..37947d39e 100644
--- a/cmstestsuite/Tests.py
+++ b/cmstestsuite/Tests.py
@@ -43,6 +43,7 @@
 LANG_CPP = "C++11 / g++"
 LANG_CPP14 = "C++14 / g++"
 LANG_CPP17 = "C++17 / g++"
+LANG_CPP20 = "C++20 / g++"
 LANG_C = "C11 / gcc"
 LANG_HS = "Haskell / ghc"
 LANG_JAVA = "Java / JDK"
@@ -52,14 +53,14 @@
 LANG_RUST = "Rust"
 LANG_C_SHARP = "C# / Mono"
 ALL_LANGUAGES = (
-    LANG_CPP, LANG_CPP14, LANG_CPP17, LANG_C, LANG_HS, LANG_JAVA, LANG_PASCAL,
+    LANG_CPP, LANG_CPP14, LANG_CPP17, LANG_CPP20, LANG_C, LANG_HS, LANG_JAVA, LANG_PASCAL,
     LANG_PHP, LANG_PYTHON3, LANG_RUST, LANG_C_SHARP
 )
 NON_INTERPRETED_LANGUAGES = (
-    LANG_C, LANG_CPP, LANG_CPP14, LANG_CPP17, LANG_PASCAL
+    LANG_C, LANG_CPP, LANG_CPP14, LANG_CPP17, LANG_CPP20, LANG_PASCAL
 )
 COMPILED_LANGUAGES = (
-    LANG_C, LANG_CPP, LANG_CPP14, LANG_CPP17, LANG_PASCAL, LANG_JAVA,
+    LANG_C, LANG_CPP, LANG_CPP14, LANG_CPP17, LANG_CPP20, LANG_PASCAL, LANG_JAVA,
     LANG_PYTHON3, LANG_HS, LANG_RUST, LANG_C_SHARP
 )
 
@@ -72,6 +73,7 @@
          alt_filenames={
              LANG_CPP14: ['correct-stdio-cxx14.%l'],
              LANG_CPP17: ['correct-stdio-cxx17.%l'],
+             LANG_CPP20: ['correct-stdio-cxx20.%l'],
          },
          languages=ALL_LANGUAGES,
          checks=[CheckOverallScore(100, 100)]),
diff --git a/cmstestsuite/code/correct-stdio-cxx20.cpp b/cmstestsuite/code/correct-stdio-cxx20.cpp
new file mode 100644
index 000000000..657724821
--- /dev/null
+++ b/cmstestsuite/code/correct-stdio-cxx20.cpp
@@ -0,0 +1,9 @@
+#include <iostream>
+
+static_assert(__cplusplus == 202002L, "C++20 expected");
+
+int main() {
+    int n;
+    std::cin >> n;
+    std::cout << "correct " << n << std::endl;
+}
diff --git a/setup.py b/setup.py
index 8ba0d4cc9..9761864d6 100755
--- a/setup.py
+++ b/setup.py
@@ -185,6 +185,7 @@ def run(self):
             "C++11 / g++=cms.grading.languages.cpp11_gpp:Cpp11Gpp",
             "C++14 / g++=cms.grading.languages.cpp14_gpp:Cpp14Gpp",
             "C++17 / g++=cms.grading.languages.cpp17_gpp:Cpp17Gpp",
+            "C++20 / g++=cms.grading.languages.cpp20_gpp:Cpp20Gpp",
             "C11 / gcc=cms.grading.languages.c11_gcc:C11Gcc",
             "C# / Mono=cms.grading.languages.csharp_mono:CSharpMono",
             "Haskell / ghc=cms.grading.languages.haskell_ghc:HaskellGhc",