diff --git a/tests/zfs-tests/cmd/mmap_seek.c b/tests/zfs-tests/cmd/mmap_seek.c
index 7be92d109565..2d250554a13f 100644
--- a/tests/zfs-tests/cmd/mmap_seek.c
+++ b/tests/zfs-tests/cmd/mmap_seek.c
@@ -35,6 +35,16 @@
 #include <linux/fs.h>
 #endif
 
+/* some older uClibc's lack the defines, so we'll manually define them */
+#ifdef	__UCLIBC__
+#ifndef	SEEK_DATA
+#define	SEEK_DATA 3
+#endif
+#ifndef	SEEK_HOLE
+#define	SEEK_HOLE 4
+#endif
+#endif
+
 static void
 seek_data(int fd, off_t offset, off_t expected)
 {
diff --git a/tests/zfs-tests/tests/functional/cp_files/seekflood.c b/tests/zfs-tests/tests/functional/cp_files/seekflood.c
index 02c2c8e6eca5..f832db85970d 100644
--- a/tests/zfs-tests/tests/functional/cp_files/seekflood.c
+++ b/tests/zfs-tests/tests/functional/cp_files/seekflood.c
@@ -36,6 +36,13 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 
+/* some older uClibc's lack the defines, so we'll manually define them */
+#ifdef	__UCLIBC__
+#ifndef	SEEK_DATA
+#define	SEEK_DATA 3
+#endif
+#endif
+
 #define	DATASIZE	(4096)
 char data[DATASIZE];