diff --git a/CMakeLists.txt b/CMakeLists.txt
index ad069449..bf2760f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -50,7 +50,7 @@ add_subdirectory(src)
 
 # Build tests only if requested
 if (BUILD_TESTING AND CATCH_BUILD_TESTING AND NOT_SUBPROJECT)
-    find_package(PythonInterp)
+    find_package(PythonInterp 3 REQUIRED)
     if (NOT PYTHONINTERP_FOUND)
         message(FATAL_ERROR "Python not found, but required for tests")
     endif()
diff --git a/appveyor.yml b/appveyor.yml
index 8e57a59c..264794fd 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -13,7 +13,7 @@ branches:
 
 # We need a more up to date pip because Python 2.7 is EOL soon
 init:
-  - set PATH=C:\Python35\Scripts;%PATH%
+  - set PATH=C:\Python35;C:\Python35\Scripts;%PATH%
 
 
 install: