1 files changed, 1 insertions, 1 deletions
diff --git a/math.c b/math.c
index 9e97f3a2d2..23c6210373 100644
--- a/math.c
+++ b/math.c
@@ -750,7 +750,7 @@ ruby_tgamma(const double d)
 #define tgamma(d) ruby_tgamma(d)
 #endif
 
-#if defined __MINGW32__ || defined __APPLE__
+#if defined _WIN32 || defined __APPLE__
 static inline double
 ruby_lgamma_r(const double d, int *sign)
 {