diff --git a/util/.gitignore b/util/.gitignore
index 6982f2d05..95b7c4db1 100644
--- a/util/.gitignore
+++ b/util/.gitignore
@@ -17,3 +17,6 @@ gif2txt
 txt2ppm
 tile2img.ttp
 xpm2ppm.ttp
+# dev tool for analyzing data collected by nethack's #define MONITOR_HEAP
+heaputil
+heaputil.c