diff --git a/poky/meta/recipes-rt/rt-tests/rt-tests_1.1.bb b/poky/meta/recipes-rt/rt-tests/rt-tests_1.1.bb
index b673cd7..5aa0aa1 100644
--- a/poky/meta/recipes-rt/rt-tests/rt-tests_1.1.bb
+++ b/poky/meta/recipes-rt/rt-tests/rt-tests_1.1.bb
@@ -14,6 +14,10 @@
             file://run-ptest \
             file://rt_bmark.py \
            "
+
+# rt-tests needs PI mutex support in libc
+COMPATIBLE_HOST_libc-musl = 'null'
+
 # Do not install hwlatdetect
 EXTRA_OEMAKE += "PYLIB=''"