diff --git a/client/ctclient/cmd/bisect.go b/client/ctclient/cmd/bisect.go
index 5e59d36617..9c9ee2a082 100644
--- a/client/ctclient/cmd/bisect.go
+++ b/client/ctclient/cmd/bisect.go
@@ -29,6 +29,7 @@ func init() {
 		Use:     fmt.Sprintf("bisect %s --timestamp=ts [--chain] [--text=false]", connectionFlags),
 		Aliases: []string{"find-timestamp"},
 		Short:   "Find a log entry by timestamp",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runBisect(cmd.Context())
 		},
diff --git a/client/ctclient/cmd/get_consistency_proof.go b/client/ctclient/cmd/get_consistency_proof.go
index b52ca629ab..f37dde086f 100644
--- a/client/ctclient/cmd/get_consistency_proof.go
+++ b/client/ctclient/cmd/get_consistency_proof.go
@@ -39,6 +39,7 @@ func init() {
 		Use:     fmt.Sprintf("get-consistency-proof %s --size=N --tree_hash=hash --prev_size=N --prev_hash=hash", connectionFlags),
 		Aliases: []string{"getconsistencyproof", "consistency-proof", "consistency"},
 		Short:   "Fetch and verify a consistency proof between two tree states",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runGetConsistencyProof(cmd.Context())
 		},
diff --git a/client/ctclient/cmd/get_entries.go b/client/ctclient/cmd/get_entries.go
index f9e567ccf5..7da7ef8fe1 100644
--- a/client/ctclient/cmd/get_entries.go
+++ b/client/ctclient/cmd/get_entries.go
@@ -39,6 +39,7 @@ func init() {
 		Use:     fmt.Sprintf("get-entries %s --first=idx [--last=idx]", connectionFlags),
 		Aliases: []string{"getentries", "entries"},
 		Short:   "Fetch a range of entries in the log",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runGetEntries(cmd.Context())
 		},
diff --git a/client/ctclient/cmd/get_inclusion_proof.go b/client/ctclient/cmd/get_inclusion_proof.go
index 8f8f201560..6e4411b990 100644
--- a/client/ctclient/cmd/get_inclusion_proof.go
+++ b/client/ctclient/cmd/get_inclusion_proof.go
@@ -46,6 +46,7 @@ func init() {
 		Use:     fmt.Sprintf("get-inclusion-proof %s {--leaf_hash=hash | --cert_chain=file} [--timestamp=ts] [--size=N]", connectionFlags),
 		Aliases: []string{"getinclusionproof", "inclusion-proof", "inclusion"},
 		Short:   "Fetch and verify the inclusion proof for an entry",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runGetInclusionProof(cmd.Context())
 		},
diff --git a/client/ctclient/cmd/get_roots.go b/client/ctclient/cmd/get_roots.go
index f3255799aa..b94646298e 100644
--- a/client/ctclient/cmd/get_roots.go
+++ b/client/ctclient/cmd/get_roots.go
@@ -26,6 +26,7 @@ func init() {
 		Use:     fmt.Sprintf("get-roots %s", connectionFlags),
 		Aliases: []string{"getroots", "roots"},
 		Short:   "Fetch the root certificates accepted by the log",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runGetRoots(cmd.Context())
 		},
diff --git a/client/ctclient/cmd/get_sth.go b/client/ctclient/cmd/get_sth.go
index 39db612df2..65b1b0ac1a 100644
--- a/client/ctclient/cmd/get_sth.go
+++ b/client/ctclient/cmd/get_sth.go
@@ -27,6 +27,7 @@ func init() {
 		Use:     fmt.Sprintf("get-sth %s", connectionFlags),
 		Aliases: []string{"sth"},
 		Short:   "Fetch the latest STH of the log",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runGetSTH(cmd.Context())
 		},
diff --git a/client/ctclient/cmd/upload.go b/client/ctclient/cmd/upload.go
index d090f5fe32..be17b7451f 100644
--- a/client/ctclient/cmd/upload.go
+++ b/client/ctclient/cmd/upload.go
@@ -33,6 +33,7 @@ func init() {
 		Use:     fmt.Sprintf("upload %s --cert_chain=file [--log_mmd=dur]", connectionFlags),
 		Aliases: []string{"add-chain"},
 		Short:   "Submit a certificate (pre-)chain to the log",
+		Args:    cobra.MaximumNArgs(0),
 		Run: func(cmd *cobra.Command, _ []string) {
 			runUpload(cmd.Context())
 		},