diff --git a/monitor/Makefile.am b/monitor/Makefile.am
index a938e00..9575244 100644
--- a/monitor/Makefile.am
+++ b/monitor/Makefile.am
@@ -31,4 +31,4 @@
 	-flto
 
 fan_monitor_defs.cpp: ${srcdir}/gen-fan-monitor-defs.py
-	$(AM_V_GEN)$(GEN_FAN_MONITOR_DEFS)
+	$(AM_V_GEN)$(GEN_FAN_MONITOR_DEFS) > ${builddir}/$@