diff --git a/src/tools/amduat_pel_cli.c b/src/tools/amduat_pel_cli.c
index 6db2bf8..2286c09 100644
--- a/src/tools/amduat_pel_cli.c
+++ b/src/tools/amduat_pel_cli.c
@@ -140,7 +140,7 @@ static void amduat_pel_cli_print_usage(FILE *stream) {
           "  - Expected type tags: program 0x00000101, trace 0x00000102, result 0x00000103.\n"
           "  - Encoding profile IDs: program 0x0101, trace 0x0102, result 0x0103.\n"
           "  - Kernel ops: pel.bytes.concat, pel.bytes.slice, pel.bytes.const, pel.bytes.hash.asl1.\n"
-          "  - --ref-format bytes expects --ref to be a path or '-' (raw reference bytes).\n"
+          "  - --ref-format bytes expects REF arguments to be a path or '-' (raw reference bytes).\n"
           "  - --inputs-file with --ref-format bytes expects raw concatenated references.\n");
 }