diff --git a/elevation_mapping_cupy/CMakeLists.txt b/elevation_mapping_cupy/CMakeLists.txt
index d93e93a7..88a43627 100644
--- a/elevation_mapping_cupy/CMakeLists.txt
+++ b/elevation_mapping_cupy/CMakeLists.txt
@@ -2,8 +2,8 @@
 cmake_minimum_required(VERSION 3.0.2)
 project(elevation_mapping_cupy)
 
-find_package(PythonInterp REQUIRED)
-find_package(PythonLibs REQUIRED)
+find_package(PythonInterp 3 REQUIRED)
+find_package(PythonLibs 3 REQUIRED)
 
 if(PYTHONLIBS_FOUND)
   message(STATUS "Using Python Libraries at: " ${PYTHON_LIBRARIES})
diff --git a/requirements.txt b/requirements.txt
index fec90ede..371ded70 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,4 +6,4 @@ ruamel.yaml
 opencv-python
 
 ###### Requirements with Version Specifiers ######`
-shapely==1.7.1
+shapely==1.7a1