diff --git a/conjure-java-undertow-runtime/src/main/java/com/palantir/conjure/java/undertow/runtime/UnclosableOutputStreams.java b/conjure-java-undertow-runtime/src/main/java/com/palantir/conjure/java/undertow/runtime/UnclosableOutputStreams.java
index 6303ebb29..2b8cf7ed3 100644
--- a/conjure-java-undertow-runtime/src/main/java/com/palantir/conjure/java/undertow/runtime/UnclosableOutputStreams.java
+++ b/conjure-java-undertow-runtime/src/main/java/com/palantir/conjure/java/undertow/runtime/UnclosableOutputStreams.java
@@ -112,6 +112,7 @@ public void write(ByteBuffer byteBuffer) throws IOException {
         }
 
         @Override
+        @SuppressWarnings("deprecation") // BufferWritableOutputStream still requires this method in Undertow 2.4.
         public void transferFrom(FileChannel source) throws IOException {
             assertOpen();
             bufferWritable.transferFrom(source);
diff --git a/versions.lock b/versions.lock
index e3877f42a..4b5c6df33 100644
--- a/versions.lock
+++ b/versions.lock
@@ -142,7 +142,7 @@ io.smallrye.common:smallrye-common-os:2.4.0 (1 constraints: b10e835a)
 
 io.smallrye.common:smallrye-common-ref:2.4.0 (1 constraints: b10e835a)
 
-io.undertow:undertow-core:2.2.38.Final (2 constraints: ea19a2fe)
+io.undertow:undertow-core:2.4.1.Final (2 constraints: b2197dec)
 
 jakarta.annotation:jakarta.annotation-api:2.1.1 (6 constraints: cd5ca708)
 
@@ -170,9 +170,9 @@ org.hdrhistogram:HdrHistogram:2.2.2 (1 constraints: 0e100092)
 
 org.immutables:value:2.12.2 (2 constraints: 0215eec1)
 
-org.jboss.logging:jboss-logging:3.6.1.Final (9 constraints: 8faed263)
+org.jboss.logging:jboss-logging:3.6.2.Final (9 constraints: 92ae8266)
 
-org.jboss.threads:jboss-threads:3.9.2 (3 constraints: a8285de8)
+org.jboss.threads:jboss-threads:3.9.2 (3 constraints: 952643f7)
 
 org.jboss.xnio:xnio-api:3.8.16.Final (2 constraints: d71a2474)
 
diff --git a/versions.props b/versions.props
index fd2f81e42..916a33012 100644
--- a/versions.props
+++ b/versions.props
@@ -22,7 +22,7 @@ com.palantir.syntactic-paths:syntactic-paths = 0.18.0
 com.palantir.tokens:* = 4.6.0
 com.palantir.tracing:* = 6.35.0
 info.picocli:picocli = 4.7.7
-io.undertow:* = 2.2.38.Final
+io.undertow:* = 2.4.1.Final
 joda-time:joda-time = 2.14.2
 org.apache.commons:commons-lang3 = 3.20.0
 org.assertj:* = 3.27.7