diff --git a/CHANGES.md b/CHANGES.md
index cd6056e..d8214d3 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -13,7 +13,7 @@ The following submodules are required:
 
 * Mac mini 2023 Apple Silicon (M2 Pro), macOS 14.2, Xcode 15.1 Command Line Tools
 * MacBook Air 13" Apple Silicon (M1) 2020, macOS 14.2, Xcode 15.1 Command Line Tools
-* Ubuntu 22.04.3 LTS x86\_64, gcc 11.4.0
+* Ubuntu 22.04.3 LTS x86\_64, gcc 11.4.0 (with VOLK 2.5.1 or 3.0.0 only)
 * (Unofficial/experimental) Raspberry Pi OS
 
 ## Features under development
@@ -23,6 +23,7 @@ The following submodules are required:
 
 ## Known limitations
 
+* **Use VOLK v3.0.0 or v2.5.1 in apt repository for Ubuntu 22.04.3.**
 * For Raspberry Pi 3 and 4, Airspy R2 10Msps and Airspy Mini 6Msps sampling rates are *not supported* due to the hardware limitation. Use in 2.5Msps for R2, 3Msps for Mini.
 
 ### Intel Mac support is dropped
@@ -31,7 +32,7 @@ Intel Mac hardware is no longer supported by airspy-fmradion, although the autho
 
 ## Changes (including requirement changes)
 
-* 20231212-1: Updated to make API compatible with [VOLK 3.1.0 change for s32fc functions](https://github.com/gnuradio/volk/pull/695), for `volk_32fc_x2_s32fc_multiply_conjugate_add_32fc()`.
+* 20231212-1: FAILED: tried to make API compatible with [VOLK 3.1.0 change for s32fc functions](https://github.com/gnuradio/volk/pull/695), for `volk_32fc_x2_s32fc_multiply_conjugate_add_32fc()`, but this didn't work on Ubuntu 22.04.3.
 * 20231212-0: Updated r8-brain-free-src to Version 6.5.
 * 20230923: failed changes: low latency setting for buffering-based PortAudio didn't work well. Discarded changes of 20230910-1 to 20230910-4 from the dev branch.
 * 20230910-0: Updated r8brain-free-src to Version 6.4.
diff --git a/INSTALL-latest-libvolk.md b/INSTALL-latest-libvolk.md
index fd47eaf..fa81fd2 100644
--- a/INSTALL-latest-libvolk.md
+++ b/INSTALL-latest-libvolk.md
@@ -16,8 +16,9 @@ brew install volk
 
 ## For Linux
 
-See [libvolk README.md](https://github.com/gnuradio/volk#readme).
-
+* For Ubuntu 22.04.3 LTS, *libvolk 3.1.0 does not work.* Use 3.0.0 or 2.5.1 in the apt repository.
+* See [libvolk README.md](https://github.com/gnuradio/volk#readme).
+ 
 ## After installation
 
 Do the full benchmark by `volk_profile -b -p .`. Use the result at `~/.volk/volk_config` for optimizing the execution.
diff --git a/README.md b/README.md
index 2f73888..72e645f 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 # airspy-fmradion
 
-* Version 20230910-0
+* Version 20231212-1
 * For MacOS (supporting Apple Silicon only, untested on Intel) and Linux
 
 ## Contributing