diff --git a/Compiling-from-source.md b/Compiling-from-source.md
index e1823d4..dc3b18e 100644
--- a/Compiling-from-source.md
+++ b/Compiling-from-source.md
@@ -246,7 +246,7 @@ You can find several examples in README.txt
 If you have a CPU with more than 64 threads and Windows 7 or higher you
 can enable the CPU Groups feature by adding the following to CFLAGS:
 
-`-D_WIN32_WINNT==0x0601`
+`-D_WIN32_WINNT=0x0601`
 
 Once you have run configure successfully run the compiler with n CPU threads: