diff --git a/clap-utils/src/offline.rs b/clap-utils/src/offline.rs
index 08f2364dfe6f07..79a5b0dba0a891 100644
--- a/clap-utils/src/offline.rs
+++ b/clap-utils/src/offline.rs
@@ -52,6 +52,7 @@ fn signer_arg<'a, 'b>() -> Arg<'a, 'b> {
         .validator(is_pubkey_sig)
         .requires(BLOCKHASH_ARG.name)
         .multiple(true)
+        .number_of_values(1)
         .help(SIGNER_ARG.help)
 }
 
diff --git a/clap-v3-utils/src/offline.rs b/clap-v3-utils/src/offline.rs
index b9ccd2d4ec4ea3..cfd71e2a6b23e5 100644
--- a/clap-v3-utils/src/offline.rs
+++ b/clap-v3-utils/src/offline.rs
@@ -53,7 +53,7 @@ fn signer_arg<'a>() -> Arg<'a> {
         .value_parser(value_parser!(PubkeySignature))
         .requires(BLOCKHASH_ARG.name)
         .multiple_occurrences(true)
-        .multiple_values(true)
+        .multiple_values(false)
         .help(SIGNER_ARG.help)
 }