diff --git a/tools/binman/README.entries b/tools/binman/README.entries
index 31bc725..5cb52a9 100644
--- a/tools/binman/README.entries
+++ b/tools/binman/README.entries
@@ -546,6 +546,11 @@
     - kernelkey: Name of the kernel key to use (inside keydir)
     - preamble-flags: Value of the vboot preamble flags (typically 0)
 
+Output files:
+    - input.<unique_name> - input file passed to futility
+    - vblock.<unique_name> - output file generated by futility (which is
+        used as the entry contents)
+
 Chromium OS signs the read-write firmware and kernel, writing the signature
 in this block. This allows U-Boot to verify that the next firmware stage
 and kernel are genuine.