diff --git a/thirdparty/libwebp/sharpyuv/sharpyuv_gamma.c b/thirdparty/libwebp/sharpyuv/sharpyuv_gamma.c
index f72be4b89e..17c4b1940b 100644
--- a/thirdparty/libwebp/sharpyuv/sharpyuv_gamma.c
+++ b/thirdparty/libwebp/sharpyuv/sharpyuv_gamma.c
@@ -27,7 +27,11 @@ static uint32_t kGammaToLinearTabS[GAMMA_TO_LINEAR_TAB_SIZE + 2];
#define LINEAR_TO_GAMMA_TAB_SIZE (1 << LINEAR_TO_GAMMA_TAB_BITS)
static uint32_t kLinearToGammaTabS[LINEAR_TO_GAMMA_TAB_SIZE + 2];
+#if defined(_MSC_VER)
+static const double kGammaF = 2.222222222222222;
+#else
static const double kGammaF = 1. / 0.45;
+#endif
#define GAMMA_TO_LINEAR_BITS 16
static volatile int kGammaTablesSOk = 0;