diff --git a/CMakeLists.txt b/CMakeLists.txt
index e176b6a7e..1c3c6f41a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -125,6 +125,7 @@ if(GTIRB_PY_API)
       COMMAND "${PYTHON}" "--version" OUTPUT_VARIABLE PYTHON_VERSION
     )
     string(REPLACE "Python" "" PYTHON_VERSION "${PYTHON_VERSION}")
+    string(STRIP "${PYTHON_VERSION}" PYTHON_VERSION)
 
     if("${PYTHON_VERSION}" VERSION_LESS "${PYTHON_MINIMUM_VERSION}")
       message(