diff --git a/presence/Makefile.am b/presence/Makefile.am
index 10a7363..b56ed4e 100644
--- a/presence/Makefile.am
+++ b/presence/Makefile.am
@@ -21,5 +21,5 @@
 
 BUILT_SOURCES = fan_detect_defs.cpp
 
-fan_detect_defs.cpp: ${srcdir}/gen-fan-detect-defs.py
-	$(AM_V_GEN)$(GEN_FAN_DETECT_DEFS) > $@
+fan_detect_defs.cpp: ${srcdir}/gen-fan-detect-defs.py $(FAN_DETECT_YAML_FILE)
+	$(AM_V_GEN)$(GEN_FAN_DETECT_DEFS) > $(builddir)/$@
diff --git a/presence/gen-fan-detect-defs.py b/presence/gen-fan-detect-defs.py
index 1bc980a..842bbeb 100755
--- a/presence/gen-fan-detect-defs.py
+++ b/presence/gen-fan-detect-defs.py
@@ -37,16 +37,6 @@
 '''
 
 
-def get_filename():
-    """
-    Constructs and returns the fully qualified header filename.
-    """
-    script_dir = os.path.dirname(os.path.abspath(__file__))
-    header_file = os.path.join(script_dir, "fan_detect_defs.cpp")
-
-    return header_file
-
-
 if __name__ == '__main__':
     parser = ArgumentParser()
     # Input yaml containing how each fan's presence detection should be done
@@ -66,7 +56,4 @@
     with open(yaml_file, 'r') as yaml_input:
         presence_data = yaml.safe_load(yaml_input) or {}
 
-    output_file = get_filename()
-
-    with open(output_file, 'w') as out:
-        out.write(Template(tmpl).render(presence=presence_data))
+    sys.stdout.write(Template(tmpl).render(presence=presence_data))