diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 8f85e15098ed..d9e04804bd7b 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -1630,10 +1630,13 @@ def get_clink_dynamic_linker_and_stdlibs(self) -> T.Tuple['Compiler', T.List[str
 
     def get_used_stdlib_args(self, link_language: str) -> T.List[str]:
         all_compilers = self.environment.coredata.compilers[self.for_machine]
-        all_langs = set(all_compilers).union(self.get_langs_used_by_deps())
+        all_langs = set(self.compilers).union(self.get_langs_used_by_deps())
         stdlib_args: T.List[str] = []
         for dl in all_langs:
             if dl != link_language and (dl, link_language) not in self._MASK_LANGS:
+                # We need to use all_compilers here because
+                # get_langs_used_by_deps could return a language from a
+                # subproject
                 stdlib_args.extend(all_compilers[dl].language_stdlib_only_link_flags(self.environment))
         return stdlib_args