diff --git a/README.md b/README.md
index d9505acd..a313c6f5 100644
--- a/README.md
+++ b/README.md
@@ -90,7 +90,7 @@ In addition to the core functionality, pybind11 provides some extra goodies:
 2. GCC (any non-ancient version with C++11 support)
 3. Microsoft Visual Studio 2015 or newer
 4. Intel C++ compiler v15 or newer
-5. Cygwin
+5. Cygwin/GCC (tested on 2.5.1)
 
 ## About