diff --git a/appveyor.yml b/appveyor.yml
index 25b95d29..b0544a90 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -47,7 +47,7 @@ before_build:
 - upx -V
 - ccache -V
 - ccache -s
-- set SRB2_MFLAGS=-C src MINGW=1 WARNINGMODE=1 GCC53=1 CCACHE=1
+- set SRB2_MFLAGS=-C src MINGW=1 WARNINGMODE=1 GCC63=1 CCACHE=1
 
 build_script:
 - cmd: mingw32-make.exe %SRB2_MFLAGS% %CONFIGURATION%=1 clean