diff --git a/src/mzscheme/src/schvers.h b/src/mzscheme/src/schvers.h
index 25e71eaded..be1a6933b1 100644
--- a/src/mzscheme/src/schvers.h
+++ b/src/mzscheme/src/schvers.h
@@ -13,12 +13,12 @@
    consistently.)
 */
 
-#define MZSCHEME_VERSION "4.2.1.8"
+#define MZSCHEME_VERSION "4.2.2.1"
 
 #define MZSCHEME_VERSION_X 4
 #define MZSCHEME_VERSION_Y 2
-#define MZSCHEME_VERSION_Z 1
-#define MZSCHEME_VERSION_W 8
+#define MZSCHEME_VERSION_Z 2
+#define MZSCHEME_VERSION_W 1
 
 #define MZSCHEME_VERSION_MAJOR ((MZSCHEME_VERSION_X * 100) + MZSCHEME_VERSION_Y)
 #define MZSCHEME_VERSION_MINOR ((MZSCHEME_VERSION_Z * 1000) + MZSCHEME_VERSION_W)