diff --git a/tools/update_signatures b/tools/update_signatures
new file mode 100755
index 00000000..4142c835
--- /dev/null
+++ b/tools/update_signatures
@@ -0,0 +1 @@
+grep -h '^sig \|^fn ' [0-9]*.mu |grep -v 'fn test-' |sed 's/^fn /sig /' |sed 's/ {$//' > signatures.mu