diff --git a/lib/libzpool/include/sys/zfs_context.h b/lib/libzpool/include/sys/zfs_context.h
index c104f6d3a1..fad26f3e94 100644
--- a/lib/libzpool/include/sys/zfs_context.h
+++ b/lib/libzpool/include/sys/zfs_context.h
@@ -205,7 +205,7 @@ _NOTE(CONSTCOND) } while (0)
  */
 #define	TS_MAGIC		0x72f158ab4261e538ull
 #define	TS_RUN			0x00000002
-#ifdef _linux_
+#ifdef __linux__
 #define	STACK_SIZE		8192	/* Linux x86 and amd64 */
 #else
 #define	STACK_SIZE		24576	/* Solaris */