diff --git a/PCbuild/build_ssl.bat b/PCbuild/build_ssl.bat
index 9aad441..3c87f82 100644
--- a/PCbuild/build_ssl.bat
+++ b/PCbuild/build_ssl.bat
@@ -4,8 +4,10 @@
 if not defined HOST_PYTHON (
   if %1 EQU Debug (
     set HOST_PYTHON=python_d.exe
+    if not exist python30_d.dll exit 1
   ) ELSE (
     set HOST_PYTHON=python.exe
+    if not exist python30.dll exit 1
   )
 )
 %HOST_PYTHON% build_ssl.py %1 %2