diff --git a/doc/release-notes-28454.md b/doc/release-notes-28454.md
new file mode 100644
index 0000000000000..6780218714c1b
--- /dev/null
+++ b/doc/release-notes-28454.md
@@ -0,0 +1,5 @@
+RPC Wallet
+----------
+
+- The `walletpassphrase` call will now uses the value of 100,000,000 seconds (~3 years)
+  if the user passes a `timeout` value of `-1`. (#28454)
diff --git a/src/wallet/rpc/encrypt.cpp b/src/wallet/rpc/encrypt.cpp
index 0226d15698bab..0d472b7e8eded 100644
--- a/src/wallet/rpc/encrypt.cpp
+++ b/src/wallet/rpc/encrypt.cpp
@@ -18,7 +18,7 @@ RPCHelpMan walletpassphrase()
             "time that overrides the old one.\n",
                 {
                     {"passphrase", RPCArg::Type::STR, RPCArg::Optional::NO, "The wallet passphrase"},
-                    {"timeout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The time to keep the decryption key in seconds; capped at 100000000 (~3 years)."},
+                    {"timeout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The time to keep the decryption key in seconds; capped at 100000000 (~3 years), will use cap if -1 specified."},
                 },
                 RPCResult{RPCResult::Type::NONE, "", ""},
                 RPCExamples{
@@ -54,12 +54,13 @@ RPCHelpMan walletpassphrase()
         // Get the timeout
         nSleepTime = request.params[1].getInt<int64_t>();
         // Timeout cannot be negative, otherwise it will relock immediately
-        if (nSleepTime < 0) {
+        if (nSleepTime < 0 && nSleepTime != -1) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Timeout cannot be negative.");
         }
         // Clamp timeout
         constexpr int64_t MAX_SLEEP_TIME = 100000000; // larger values trigger a macos/libevent bug?
-        if (nSleepTime > MAX_SLEEP_TIME) {
+
+        if (nSleepTime > MAX_SLEEP_TIME || nSleepTime == -1) {
             nSleepTime = MAX_SLEEP_TIME;
         }
 
diff --git a/test/functional/test_framework/wallet_util.py b/test/functional/test_framework/wallet_util.py
index 44811918bf946..9c16371148723 100755
--- a/test/functional/test_framework/wallet_util.py
+++ b/test/functional/test_framework/wallet_util.py
@@ -128,9 +128,7 @@ class WalletUnlock():
     A context manager for unlocking a wallet with a passphrase and automatically locking it afterward.
     """
 
-    MAXIMUM_TIMEOUT = 999000
-
-    def __init__(self, wallet, passphrase, timeout=MAXIMUM_TIMEOUT):
+    def __init__(self, wallet, passphrase, timeout=-1):
         self.wallet = wallet
         self.passphrase = passphrase
         self.timeout = timeout