diff --git a/meta/recipes-extended/mdadm/mdadm_3.2.6.bb b/meta/recipes-extended/mdadm/mdadm_3.2.6.bb
index 50f39dbc0d..382c0c128a 100644
--- a/meta/recipes-extended/mdadm/mdadm_3.2.6.bb
+++ b/meta/recipes-extended/mdadm/mdadm_3.2.6.bb
@@ -27,6 +27,11 @@ do_configure_prepend () {
 }
 
 EXTRA_OEMAKE = "CHECK_RUN_DIR=0"
+# PPC64 uses long long for u64 in the kernel, but powerpc's asm/types.h
+# prevents 64-bit userland from seeing this definition, instead defaulting
+# to u64 == long in userspace. Define __SANE_USERSPACE_TYPES__ to get
+# int-ll64.h included
+EXTRA_OEMAKE_append_powerpc64 = ' CFLAGS=-D__SANE_USERSPACE_TYPES__'
 
 do_compile() {
 	oe_runmake