diff --git a/src/core/sys/windows/winhttp.d b/src/core/sys/windows/winhttp.d
index 9a7592265c..cacc25d9a0 100644
--- a/src/core/sys/windows/winhttp.d
+++ b/src/core/sys/windows/winhttp.d
@@ -654,7 +654,7 @@ enum : DWORD {
     ERROR_WINHTTP_CONNECTION_ERROR       = (WINHTTP_ERROR_BASE + 30),
     ERROR_WINHTTP_RESEND_REQUEST         = (WINHTTP_ERROR_BASE + 32),
 
-    ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED = (WINHTTP_ERROR_BASE, + 44),
+    ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED = (WINHTTP_ERROR_BASE + 44),
 
     ERROR_WINHTTP_CANNOT_CALL_BEFORE_OPEN = (WINHTTP_ERROR_BASE + 100),
     ERROR_WINHTTP_CANNOT_CALL_BEFORE_SEND = (WINHTTP_ERROR_BASE + 101),