diff --git a/lib/portability.h b/lib/portability.h
index b38d881..b7a7c79 100644
--- a/lib/portability.h
+++ b/lib/portability.h
@@ -126,6 +126,12 @@
 
 #endif
 
+#ifdef __MUSL__
+#include <unistd.h>
+// Without this "rm -r dir" fails with "is directory".
+#define faccessat(A, B, C, D) faccessat(A, B, C, 0)
+#endif
+
 // Work out how to do endianness
 
 #ifndef __APPLE__