diff --git a/config/kernel-copy-from-user-inatomic.m4 b/config/kernel-copy-from-user-inatomic.m4
index 5fddaca59..fec354b2f 100644
--- a/config/kernel-copy-from-user-inatomic.m4
+++ b/config/kernel-copy-from-user-inatomic.m4
@@ -18,9 +18,12 @@ AC_DEFUN([ZFS_AC_KERNEL___COPY_FROM_USER_INATOMIC], [
 	AC_MSG_CHECKING([whether __copy_from_user_inatomic is available])
 	ZFS_LINUX_TEST_RESULT([__copy_from_user_inatomic_license], [
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE___COPY_FROM_USER_INATOMIC, 1,
-		    [__copy_from_user_inatomic is available])
 	], [
 		AC_MSG_RESULT(no)
+		AC_MSG_ERROR([
+	*** The `__copy_from_user_inatomic()` Linux kernel function is
+	*** incompatible with the CDDL license and will prevent the module
+	*** linking stage from succeeding.  OpenZFS cannot be compiled.
+		])
 	])
 ])
diff --git a/module/os/linux/zfs/zfs_uio.c b/module/os/linux/zfs/zfs_uio.c
index 0d4b4c583..4f31bcb59 100644
--- a/module/os/linux/zfs/zfs_uio.c
+++ b/module/os/linux/zfs/zfs_uio.c
@@ -75,7 +75,6 @@ zfs_uiomove_iov(void *p, size_t n, zfs_uio_rw_t rw, zfs_uio_t *uio)
 			} else {
 				unsigned long b_left = 0;
 				if (uio->uio_fault_disable) {
-#if defined(HAVE___COPY_FROM_USER_INATOMIC)
 					if (!zfs_access_ok(VERIFY_READ,
 					    (iov->iov_base + skip), cnt)) {
 						return (EFAULT);
@@ -85,9 +84,6 @@ zfs_uiomove_iov(void *p, size_t n, zfs_uio_rw_t rw, zfs_uio_t *uio)
 					    __copy_from_user_inatomic(p,
 					    (iov->iov_base + skip), cnt);
 					pagefault_enable();
-#else
-					return (EFAULT);
-#endif
 				} else {
 					b_left =
 					    copy_from_user(p,