diff --git a/Cargo.lock b/Cargo.lock
index 7fef1012b5f..0d2a9dd8ae6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9428,9 +9428,9 @@ dependencies = [
 
 [[package]]
 name = "sphinx-packet"
-version = "0.3.1"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "535f2c430778bf59c22249fcc1ed6d384129eb2f0f694706015d636c688f9ac6"
+checksum = "ec6b227c9167ef91b9c426d7a894e9937d30efbfab0b22f31ff1c28c78c5b6f6"
 dependencies = [
  "aes",
  "arrayref",
@@ -9439,7 +9439,6 @@ dependencies = [
  "byteorder",
  "chacha",
  "ctr",
- "curve25519-dalek 4.1.3",
  "digest 0.10.7",
  "hkdf",
  "hmac",
diff --git a/Cargo.toml b/Cargo.toml
index 1cae64acf16..e10f79d1806 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -321,7 +321,7 @@ serde_with = "3.9.0"
 serde_yaml = "0.9.25"
 sha2 = "0.10.8"
 si-scale = "0.2.3"
-sphinx-packet = "0.3.1"
+sphinx-packet = "=0.4.0" # make sure to use version 0.4.0 (or higher) that has removed backwards compatibility
 sqlx = "0.7.4"
 strum = "0.26"
 strum_macros = "0.26"
diff --git a/common/nymsphinx/types/src/lib.rs b/common/nymsphinx/types/src/lib.rs
index c9441dbc4dc..517e45e783b 100644
--- a/common/nymsphinx/types/src/lib.rs
+++ b/common/nymsphinx/types/src/lib.rs
@@ -30,7 +30,6 @@ pub use sphinx_packet::{
     route::{Destination, DestinationAddressBytes, Node, NodeAddressBytes, SURBIdentifier},
     surb::{SURBMaterial, SURB},
     version::Version,
-    version::UPDATED_LEGACY_VERSION,
     Error as SphinxError, ProcessedPacket, ProcessedPacketData,
 };
 
@@ -91,12 +90,8 @@ impl NymPacket {
         destination: &Destination,
         delays: &[Delay],
     ) -> Result<NymPacket, NymPacketError> {
-        // FIXME:
-        // for now explicitly use the legacy version until sufficient number of nodes
-        // understand both variants
         Ok(NymPacket::Sphinx(
             SphinxPacketBuilder::new()
-                .with_version(UPDATED_LEGACY_VERSION)
                 .with_payload_size(size)
                 .build_packet(message, route, destination, delays)?,
         ))