diff --git a/CMakeLists.txt b/CMakeLists.txt
index 394583b..e70575d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -88,6 +88,7 @@ set(GR_PKG_CONF_DIR     ${GR_CONF_DIR}/${CMAKE_PROJECT_NAME}/conf.d)
 set(GR_LIBEXEC_DIR      libexec)
 set(GR_PKG_LIBEXEC_DIR  ${GR_LIBEXEC_DIR}/${CMAKE_PROJECT_NAME})
 set(GRC_BLOCKS_DIR      ${GR_PKG_DATA_DIR}/grc/blocks)
+set(GR_PYTHON3_MIN_VERSION "3.4")
 
 ########################################################################
 # On Apple only, set install name and use rpath correctly, if not already set