diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index 74e2b95c99ca46..7eade5bcba6d37 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -13,7 +13,7 @@
 **********************************************************************/
 
 static const char *const
-STRINGIO_VERSION = "3.1.1";
+STRINGIO_VERSION = "3.1.0";
 
 #include "ruby.h"
 #include "ruby/io.h"
diff --git a/ext/strscan/strscan.c b/ext/strscan/strscan.c
index a2bf56ce4fe111..16d669d8a5860a 100644
--- a/ext/strscan/strscan.c
+++ b/ext/strscan/strscan.c
@@ -22,7 +22,7 @@ extern size_t onig_region_memsize(const struct re_registers *regs);
 
 #include <stdbool.h>
 
-#define STRSCAN_VERSION "3.0.8"
+#define STRSCAN_VERSION "3.0.7"
 
 /* =======================================================================
                          Data Type Definitions