diff --git a/Makefile b/Makefile
index ec8769a..7723069 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ SOURCES = sources
 CONFIG_SUB_REV = 3d5db9ebe860
 BINUTILS_VER = 2.27
 GCC_VER = 6.4.0
-MUSL_VER = 1.1.20
+MUSL_VER = 1.1.21
 GMP_VER = 6.1.1
 MPC_VER = 1.0.3
 MPFR_VER = 3.1.4