diff --git a/tools/invocation_header_gen.py b/tools/invocation_header_gen.py
index 3ba760803..88a0d129b 100755
--- a/tools/invocation_header_gen.py
+++ b/tools/invocation_header_gen.py
@@ -163,7 +163,7 @@ def generate(args, invocations):
     # version which supports it.
     jinja2_version = version("jinja2")
     if jinja2_version < "2.10":
-        sys.exit("Jinja2 should be >= 2.10")
+        raise Warning("Jinja2 should be >= 2.10")
 
     header_title = "API"
     if args.libsel4:
diff --git a/tools/syscall_header_gen.py b/tools/syscall_header_gen.py
index 710840080..31e25cecf 100755
--- a/tools/syscall_header_gen.py
+++ b/tools/syscall_header_gen.py
@@ -210,7 +210,7 @@ def generate_kernel_file(kernel_header, api, debug):
     # version which supports it.
     jinja2_version = version("jinja2")
     if jinja2_version < "2.10":
-        sys.exit("Jinja2 should be >= 2.10")
+        raise Warning("Jinja2 should be >= 2.10")
 
     template = Environment(loader=BaseLoader, trim_blocks=False,
                            lstrip_blocks=False).from_string(KERNEL_HEADER_TEMPLATE)