diff --git a/meson.build b/meson.build
index e3ee957fd5..6d576b4d20 100644
--- a/meson.build
+++ b/meson.build
@@ -560,6 +560,10 @@ conf.set10('HAVE_WARNING_ZERO_AS_NULL_POINTER_CONSTANT', have)
 conf.set('_GNU_SOURCE', 1)
 conf.set('__SANE_USERSPACE_TYPES__', true)
 
+# glibc always defines _LARGEFILE64_SOURCE when _GNU_SOURCE is set, but musl does not do that,
+# and it is necessary for making getdents64() and struct dirent64 exist.
+conf.set('_LARGEFILE64_SOURCE', 1)
+
 conf.set('SIZEOF_DEV_T', cc.sizeof('dev_t', prefix : '#include <sys/types.h>'))
 conf.set('SIZEOF_INO_T', cc.sizeof('ino_t', prefix : '#include <sys/types.h>'))
 conf.set('SIZEOF_RLIM_T', cc.sizeof('rlim_t', prefix : '#include <sys/resource.h>'))