Bump version 5.1.0alpha.
diff --git a/src/liblzma/api/lzma/version.h b/src/liblzma/api/lzma/version.h
index 25e8a82..a908ea2 100644
--- a/src/liblzma/api/lzma/version.h
+++ b/src/liblzma/api/lzma/version.h
@@ -21,9 +21,9 @@
  * Version number split into components
  */
 #define LZMA_VERSION_MAJOR 5
-#define LZMA_VERSION_MINOR 0
+#define LZMA_VERSION_MINOR 1
 #define LZMA_VERSION_PATCH 0
-#define LZMA_VERSION_STABILITY LZMA_VERSION_STABILITY_STABLE
+#define LZMA_VERSION_STABILITY LZMA_VERSION_STABILITY_ALPHA
 
 #ifndef LZMA_VERSION_COMMIT
 #	define LZMA_VERSION_COMMIT ""