diff --git a/common/json_tok.c b/common/json_tok.c
index 6868b2752..e163f23fc 100644
--- a/common/json_tok.c
+++ b/common/json_tok.c
@@ -4,6 +4,7 @@
 #include <ccan/tal/str/str.h>
 #include <common/amount.h>
 #include <common/json_command.h>
+#include <common/json_helpers.h>
 #include <common/json_tok.h>
 #include <common/jsonrpc_errors.h>
 #include <common/param.h>
@@ -199,3 +200,17 @@ struct command_result *param_sat_or_all(struct command *cmd, const char *name,
 	}
 	return param_sat(cmd, name, buffer, tok, sat);
 }
+
+struct command_result *param_node_id(struct command *cmd, const char *name,
+		                     const char *buffer, const jsmntok_t *tok,
+				     struct node_id **id)
+{
+	*id = tal(cmd, struct node_id);
+	if (json_to_node_id(buffer, tok, *id))
+		return NULL;
+
+	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			    "'%s' should be a node id, not '%.*s'",
+			    name, json_tok_full_len(tok),
+			    json_tok_full(buffer, tok));
+}
diff --git a/common/json_tok.h b/common/json_tok.h
index 6a15c30ef..8ff5322bf 100644
--- a/common/json_tok.h
+++ b/common/json_tok.h
@@ -4,6 +4,7 @@
 #include "config.h"
 #include <ccan/short_types/short_types.h>
 #include <common/json.h>
+#include <common/node_id.h>
 
 struct amount_msat;
 struct amount_sat;
@@ -80,6 +81,14 @@ struct command_result *param_sat_or_all(struct command *cmd, const char *name,
 					const char *buffer, const jsmntok_t *tok,
 					struct amount_sat **sat);
 
+
+/* Extract node_id from this string. Makes sure *id is valid. */
+struct command_result *param_node_id(struct command *cmd,
+				     const char *name,
+				     const char *buffer,
+				     const jsmntok_t *tok,
+				     struct node_id **id);
+
 /*
  * Set the address of @out to @tok.  Used as a callback by handlers that
  * want to unmarshal @tok themselves.
diff --git a/common/test/run-param.c b/common/test/run-param.c
index 3bbf05139..2aa533626 100644
--- a/common/test/run-param.c
+++ b/common/test/run-param.c
@@ -42,6 +42,10 @@ struct command_result *command_fail(struct command *cmd,
 /* Generated stub for fromwire_fail */
 const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
+/* Generated stub for json_to_node_id */
+bool json_to_node_id(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
+			       struct node_id *id UNNEEDED)
+{ fprintf(stderr, "json_to_node_id called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
 /* We do this lightningd-style: */
diff --git a/lightningd/json.c b/lightningd/json.c
index f811c6e3e..7ec0b1399 100644
--- a/lightningd/json.c
+++ b/lightningd/json.c
@@ -77,23 +77,6 @@ void json_add_txid(struct json_stream *result, const char *fieldname,
 	json_add_string(result, fieldname, hex);
 }
 
-struct command_result *param_node_id(struct command *cmd,
-				     const char *name,
-				     const char *buffer,
-				     const jsmntok_t *tok,
-				     struct node_id **id)
-{
-	*id = tal(cmd, struct node_id);
-	if (json_to_node_id(buffer, tok, *id))
-		return NULL;
-
-	return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
-			    "'%s' should be a node id, not '%.*s'",
-			    name, json_tok_full_len(tok),
-			    json_tok_full(buffer, tok));
-}
-
-
 struct command_result *param_pubkey(struct command *cmd, const char *name,
 				    const char *buffer, const jsmntok_t *tok,
 				    struct pubkey **pubkey)
diff --git a/lightningd/json.h b/lightningd/json.h
index 1eaaf92d6..6ede9b5fc 100644
--- a/lightningd/json.h
+++ b/lightningd/json.h
@@ -64,12 +64,6 @@ struct command_result *param_pubkey(struct command *cmd, const char *name,
 struct command_result *param_txid(struct command *cmd, const char *name,
 				  const char *buffer, const jsmntok_t *tok,
 				  struct bitcoin_txid **txid);
-/* Makes sure *id is valid. */
-struct command_result *param_node_id(struct command *cmd,
-					       const char *name,
-					       const char *buffer,
-					       const jsmntok_t *tok,
-					       struct node_id **id);
 
 struct command_result *param_short_channel_id(struct command *cmd,
 					      const char *name,
diff --git a/lightningd/test/run-jsonrpc.c b/lightningd/test/run-jsonrpc.c
index 018e027f8..d78959a69 100644
--- a/lightningd/test/run-jsonrpc.c
+++ b/lightningd/test/run-jsonrpc.c
@@ -30,10 +30,6 @@ const char *feerate_name(enum feerate feerate UNNEEDED)
 /* Generated stub for fmt_wireaddr_without_port */
 char *fmt_wireaddr_without_port(const tal_t *ctx UNNEEDED, const struct wireaddr *a UNNEEDED)
 { fprintf(stderr, "fmt_wireaddr_without_port called!\n"); abort(); }
-/* Generated stub for json_to_node_id */
-bool json_to_node_id(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-			       struct node_id *id UNNEEDED)
-{ fprintf(stderr, "json_to_node_id called!\n"); abort(); }
 /* Generated stub for json_to_pubkey */
 bool json_to_pubkey(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
 		    struct pubkey *pubkey UNNEEDED)