diff --git a/README.md b/README.md
index 6cbc930..8ac363e 100644
--- a/README.md
+++ b/README.md
@@ -74,7 +74,7 @@
 make
 ```
 
-For Visual Studio 2019, you can now either use the CMakeLists.txt file or the included `basisu.sln` file.
+For Visual Studio 2019, you can now either use the CMakeLists.txt file or the included `basisu.sln` file. Earlier versions of Visual Studio (particularly 2017) should work but aren't actively tested. We develop with the most up to date version of 2019.
 
 To compress a sRGB PNG/BMP/TGA/JPEG image to an ETC1S .KTX2 file: