diff --git a/rosidl_typesupport_fastrtps_c/cmake/rosidl_typesupport_fastrtps_c_generate_interfaces.cmake b/rosidl_typesupport_fastrtps_c/cmake/rosidl_typesupport_fastrtps_c_generate_interfaces.cmake
index 7e093a4..5f4ce55 100644
--- a/rosidl_typesupport_fastrtps_c/cmake/rosidl_typesupport_fastrtps_c_generate_interfaces.cmake
+++ b/rosidl_typesupport_fastrtps_c/cmake/rosidl_typesupport_fastrtps_c_generate_interfaces.cmake
@@ -77,6 +77,22 @@ rosidl_write_generator_arguments(
   TARGET_DEPENDENCIES ${target_dependencies}
 )
 
+# By default, without the settings below, find_package(Python3) will attempt
+# to find the newest python version it can, and additionally will find the
+# most specific version.  For instance, on a system that has
+# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
+# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
+# The behavior we want is to prefer the "system" installed version unless the
+# user specifically tells us otherwise through the Python3_EXECUTABLE hint.
+# Setting CMP0094 to NEW means that the search will stop after the first
+# python version is found.  Setting Python3_FIND_UNVERSIONED_NAMES means that
+# the search will prefer /usr/bin/python3 over /usr/bin/python3.11.  And that
+# latter functionality is only available in CMake 3.20 or later, so we need
+# at least that version.
+cmake_minimum_required(VERSION 3.20)
+cmake_policy(SET CMP0094 NEW)
+set(Python3_FIND_UNVERSIONED_NAMES FIRST)
+
 find_package(Python3 REQUIRED COMPONENTS Interpreter)
 
 add_custom_command(
diff --git a/rosidl_typesupport_fastrtps_cpp/cmake/rosidl_typesupport_fastrtps_cpp_generate_interfaces.cmake b/rosidl_typesupport_fastrtps_cpp/cmake/rosidl_typesupport_fastrtps_cpp_generate_interfaces.cmake
index e8413c2..081cadb 100644
--- a/rosidl_typesupport_fastrtps_cpp/cmake/rosidl_typesupport_fastrtps_cpp_generate_interfaces.cmake
+++ b/rosidl_typesupport_fastrtps_cpp/cmake/rosidl_typesupport_fastrtps_cpp_generate_interfaces.cmake
@@ -87,6 +87,22 @@ rosidl_write_generator_arguments(
   TARGET_DEPENDENCIES ${target_dependencies}
 )
 
+# By default, without the settings below, find_package(Python3) will attempt
+# to find the newest python version it can, and additionally will find the
+# most specific version.  For instance, on a system that has
+# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
+# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
+# The behavior we want is to prefer the "system" installed version unless the
+# user specifically tells us otherwise through the Python3_EXECUTABLE hint.
+# Setting CMP0094 to NEW means that the search will stop after the first
+# python version is found.  Setting Python3_FIND_UNVERSIONED_NAMES means that
+# the search will prefer /usr/bin/python3 over /usr/bin/python3.11.  And that
+# latter functionality is only available in CMake 3.20 or later, so we need
+# at least that version.
+cmake_minimum_required(VERSION 3.20)
+cmake_policy(SET CMP0094 NEW)
+set(Python3_FIND_UNVERSIONED_NAMES FIRST)
+
 find_package(Python3 REQUIRED COMPONENTS Interpreter)
 
 # Add a command that invokes generator at build time