diff --git a/lib/libspl/include/assert.h b/lib/libspl/include/assert.h
index 19b25f7dd825..1b8f6befb9d5 100644
--- a/lib/libspl/include/assert.h
+++ b/lib/libspl/include/assert.h
@@ -34,7 +34,7 @@
 #include <stdarg.h>
 
 #ifndef _KERNEL
-int aok;
+extern int aok;
 #endif
 
 static inline int
diff --git a/lib/libspl/zone.c b/lib/libspl/zone.c
index 5ca93b224d9e..fb33ebaee7f8 100644
--- a/lib/libspl/zone.c
+++ b/lib/libspl/zone.c
@@ -27,6 +27,8 @@
 #include <string.h>
 #include <errno.h>
 
+int aok;
+
 zoneid_t
 getzoneid()
 {
diff --git a/tests/zfs-tests/tests/functional/checksum/edonr_test.c b/tests/zfs-tests/tests/functional/checksum/edonr_test.c
index a88756091e3d..d4a7079c669f 100644
--- a/tests/zfs-tests/tests/functional/checksum/edonr_test.c
+++ b/tests/zfs-tests/tests/functional/checksum/edonr_test.c
@@ -40,6 +40,8 @@
 #include <sys/time.h>
 #include <sys/stdtypes.h>
 
+int aok;
+
 /*
  * Test messages from:
  * http://csrc.nist.gov/groups/ST/toolkit/documents/Examples/SHA_All.pdf