diff --git a/scripts/irq2nvic_h b/scripts/irq2nvic_h
index 92d63b85..1259864f 100755
--- a/scripts/irq2nvic_h
+++ b/scripts/irq2nvic_h
@@ -27,6 +27,8 @@ method to achive the same thing with C preprocessor is known to the author.
 (Neither is any non-portable method, for that matter.)"""
 
 import sys
+import os
+import os.path
 import yaml
 
 template_nvic_h = '''\
@@ -112,12 +114,23 @@ def convert(infile, outfile_nvic, outfile_vectornvic):
     outfile_nvic.write(template_nvic_h.format(**data))
     outfile_vectornvic.write(template_vector_nvic_c.format(**data))
 
+def makeparentdir(filename):
+    try:
+        os.makedirs(os.path.dirname(filename))
+    except OSError:
+        # where is my 'mkdir -p'?
+        pass
+
 def main():
     infile = sys.argv[1]
     if not infile.startswith('./include/libopencm3/') or not infile.endswith('/irq.yaml'):
         raise ValueError("Arguent must match ./include/libopencm3/**/irq.yaml")
     nvic_h = infile.replace('irq.yaml', 'nvic.h')
     vector_nvic_c = infile.replace('./include/libopencm3/', './lib/').replace('irq.yaml', 'vector_nvic.c')
+
+    makeparentdir(nvic_h)
+    makeparentdir(vector_nvic_c)
+
     convert(open(infile), open(nvic_h, 'w'), open(vector_nvic_c, 'w'))
 
 if __name__ == "__main__":