diff --git a/mesonbuild/compilers/c.py b/mesonbuild/compilers/c.py
index 4f4860aed..d62e16335 100644
--- a/mesonbuild/compilers/c.py
+++ b/mesonbuild/compilers/c.py
@@ -51,7 +51,7 @@ else:
 
 ALL_STDS = ['c89', 'c9x', 'c90', 'c99', 'c1x', 'c11', 'c17', 'c18', 'c2x', 'c23', 'c2y']
 ALL_STDS += [f'gnu{std[1:]}' for std in ALL_STDS]
-ALL_STDS += ['iso9899:1990', 'iso9899:199409', 'iso9899:1999', 'iso9899:2011', 'iso9899:2017', 'iso9899:2018']
+ALL_STDS += ['iso9899:1990', 'iso9899:199409', 'iso9899:1999', 'iso9899:2011', 'iso9899:2017', 'iso9899:2018', 'iso9899:2024']
 
 
 class CCompiler(CLikeCompiler, Compiler):
diff --git a/mesonbuild/compilers/cpp.py b/mesonbuild/compilers/cpp.py
index acc2a3da2..f43dbe7b9 100644
--- a/mesonbuild/compilers/cpp.py
+++ b/mesonbuild/compilers/cpp.py
@@ -45,7 +45,8 @@ if T.TYPE_CHECKING:
 else:
     CompilerMixinBase = object
 
-ALL_STDS = ['c++98', 'c++0x', 'c++03', 'c++1y', 'c++1z', 'c++11', 'c++14', 'c++17', 'c++2a', 'c++20', 'c++23', 'c++26']
+ALL_STDS = ['c++98', 'c++0x', 'c++03', 'c++1y', 'c++1z', 'c++11', 'c++14', 'c++17']
+ALL_STDS += ['c++2a', 'c++2b', 'c++2c', 'c++20', 'c++23', 'c++26']
 ALL_STDS += [f'gnu{std[1:]}' for std in ALL_STDS]
 ALL_STDS += ['vc++11', 'vc++14', 'vc++17', 'vc++20', 'vc++latest', 'c++latest']