diff --git a/appveyor.yml b/appveyor.yml
index 77c99b64..90d87b6d 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -17,10 +17,11 @@ environment:
   - MSYSTEM: MINGW32
 
 install:
+- c:\msys64\usr\bin\bash -lc "pacman --needed -Sy bash pacman pacman-mirrors msys2-runtime"
 - if "%MSYSTEM%" == "MINGW64" (
-    C:\msys64\usr\bin\bash -lc "pacman --noconfirm -S mingw-w64-x86_64-boost mingw-w64-x86_64-openssl mingw-w64-x86_64-miniupnpc"
+    c:\msys64\usr\bin\bash -lc "pacman --noconfirm -S mingw-w64-x86_64-boost mingw-w64-x86_64-openssl mingw-w64-x86_64-miniupnpc"
   ) else (
-    C:\msys64\usr\bin\bash -lc "pacman --noconfirm -S mingw-w64-i686-boost mingw-w64-i686-openssl mingw-w64-i686-miniupnpc"
+    c:\msys64\usr\bin\bash -lc "pacman --noconfirm -S mingw-w64-i686-boost mingw-w64-i686-openssl mingw-w64-i686-miniupnpc"
   )
 
 build_script: