diff --git a/README.md b/README.md
index 105241382..62c11cf0d 100644
--- a/README.md
+++ b/README.md
@@ -50,13 +50,15 @@ Other features include:
  - Automatic loading/applying of PPF patches.
 
 ## System Requirements
- - A CPU faster than a potato. But it needs to be x86_64, AArch32/armv7, AArch64/ARMv8, or RISC-V/RV64.
+ - A CPU faster than a potato. But it needs to be x86_64 (SSE4.1), AArch32/armv7, AArch64/ARMv8, or RISC-V/RV64.
  - For the hardware renderers, a GPU capable of OpenGL 3.1/OpenGL ES 3.1/Direct3D 11 Feature Level 10.0 (or Vulkan 1.0) and above. So, basically anything made in the last 10 years or so.
  - SDL, XInput or DInput compatible game controller (e.g. XB360/XBOne/XBSeries). DualShock 3 users on Windows will need to install the official DualShock 3 drivers included as part of PlayStation Now.
 
 ## Downloading and running
 Binaries of DuckStation for Windows x64/ARM64, Linux x86_64 (in AppImage/Flatpak formats), and macOS Universal Binaries are available via GitHub Releases and are automatically built with every commit/push. Binaries or packages distributed through other sources may be out of date and are not supported by the developer, please speak to them for support, not us.
 
+For x86 machines (most systems), you will need a CPU that supports the SSE4.1 instruction set. This includes all CPUs manufactured after 2007. If you want to use DuckStation with a CPU that is older, [v0.1-6995](https://github.com/stenzek/duckstation/releases/tag/latest) is the last version that does not require SSE4.1.
+
 ### Windows
 
 DuckStation **requires** Windows 10/11, specifically version 1809 or newer. If you are still using Windows 7/8/8.1, DuckStation **will not run** on your operating system. Running these operating systems in 2023 should be considered a security risk, and I would recommend updating to something which receives vendor support.