diff --git a/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c b/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c
index 909f8552f603..fb1d6f89aeb7 100644
--- a/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c
+++ b/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c
@@ -32,6 +32,7 @@
 #include <string.h>
 #include <zlib.h>
 #include <libgen.h>
+#include <sys/assfail.h>
 #include <sys/spa.h>
 #include <sys/stat.h>
 #include <sys/processor.h>
diff --git a/sys/cddl/compat/opensolaris/sys/assfail.h b/sys/cddl/compat/opensolaris/sys/assfail.h
index 553da6983538..4f10a878d372 100644
--- a/sys/cddl/compat/opensolaris/sys/assfail.h
+++ b/sys/cddl/compat/opensolaris/sys/assfail.h
@@ -48,7 +48,9 @@ void assfail3(const char *, uintmax_t, const char *, uintmax_t, const char *,
 #ifndef HAVE_ASSFAIL
 extern int aok;
 
-static __inline int
+__inline int __assfail(const char *expr, const char *file, int line);
+
+__inline int
 __assfail(const char *expr, const char *file, int line)
 {