diff --git a/Makefile b/Makefile
index 16553117..b6bb6fd2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 
-export FW_VER := 3.14a
+export FW_VER := 3.15
 
 PROJ := FlashFloppy
 VER := v$(FW_VER)
diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 27f7f2ab..b7ff8cbd 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -3,6 +3,10 @@
 ** Keir Fraser <keir.xen@gmail.com>
 ************************************
 
+** v3.15 - 23 July 2020
+ - New stable release series
+ - Improve rotary encoder robustness by sampling at 4x higher rate
+
 ** v3.14a - 15 July 2020
  - Properly implement non-existent tracks as empty / unformatted
    - In particular this avoids writing tracks beyond end of disk image