diff --git a/components/camel-pqc/src/main/java/org/apache/camel/component/pqc/PQCProducer.java b/components/camel-pqc/src/main/java/org/apache/camel/component/pqc/PQCProducer.java
index a008b38966dde..df67f451af21e 100644
--- a/components/camel-pqc/src/main/java/org/apache/camel/component/pqc/PQCProducer.java
+++ b/components/camel-pqc/src/main/java/org/apache/camel/component/pqc/PQCProducer.java
@@ -16,6 +16,7 @@
  */
 package org.apache.camel.component.pqc;
 
+import java.nio.charset.StandardCharsets;
 import java.security.*;
 import java.security.cert.Certificate;
 
@@ -129,7 +130,7 @@ private void signature(Exchange exchange)
         String payload = exchange.getMessage().getMandatoryBody(String.class);
 
         signer.initSign(keyPair.getPrivate());
-        signer.update(payload.getBytes());
+        signer.update(payload.getBytes(StandardCharsets.UTF_8));
 
         byte[] signature = signer.sign();
         exchange.getMessage().setHeader(PQCConstants.SIGNATURE, signature);
@@ -140,7 +141,7 @@ private void verification(Exchange exchange)
         String payload = exchange.getMessage().getMandatoryBody(String.class);
 
         signer.initVerify(keyPair.getPublic());
-        signer.update(payload.getBytes());
+        signer.update(payload.getBytes(StandardCharsets.UTF_8));
         if (signer.verify(exchange.getMessage().getHeader(PQCConstants.SIGNATURE, byte[].class))) {
             exchange.getMessage().setHeader(PQCConstants.VERIFY, true);
         } else {
diff --git a/components/camel-pqc/src/test/java/org/apache/camel/component/pqc/PQCSignatureCharsetTest.java b/components/camel-pqc/src/test/java/org/apache/camel/component/pqc/PQCSignatureCharsetTest.java
new file mode 100644
index 0000000000000..8b62de6091853
--- /dev/null
+++ b/components/camel-pqc/src/test/java/org/apache/camel/component/pqc/PQCSignatureCharsetTest.java
@@ -0,0 +1,122 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.component.pqc;
+
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.Security;
+import java.security.Signature;
+
+import org.apache.camel.BindToRegistry;
+import org.apache.camel.EndpointInject;
+import org.apache.camel.Produce;
+import org.apache.camel.ProducerTemplate;
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.component.mock.MockEndpoint;
+import org.apache.camel.test.junit5.CamelTestSupport;
+import org.bouncycastle.jcajce.spec.MLDSAParameterSpec;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.pqc.jcajce.provider.BouncyCastlePQCProvider;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * A String body must be signed as UTF-8, not with the JVM default charset, so that a signature produced on one JVM
+ * verifies on another with a different default. This pins the UTF-8 contract by verifying the produced signature
+ * independently over the UTF-8 bytes of the payload (and confirming it does not match the ISO-8859-1 bytes).
+ */
+public class PQCSignatureCharsetTest extends CamelTestSupport {
+
+    private static final String NON_ASCII = "héllo wörld — ünïcode";
+
+    private KeyPair keyPair;
+
+    @EndpointInject("mock:sign")
+    protected MockEndpoint resultSign;
+
+    @Produce("direct:sign")
+    protected ProducerTemplate templateSign;
+
+    @BeforeAll
+    public static void startup() {
+        if (Security.getProvider(BouncyCastleProvider.PROVIDER_NAME) == null) {
+            Security.addProvider(new BouncyCastleProvider());
+        }
+        if (Security.getProvider(BouncyCastlePQCProvider.PROVIDER_NAME) == null) {
+            Security.addProvider(new BouncyCastlePQCProvider());
+        }
+    }
+
+    @Override
+    protected RouteBuilder createRouteBuilder() {
+        return new RouteBuilder() {
+            @Override
+            public void configure() {
+                from("direct:sign").to("pqc:sign?operation=sign").to("mock:sign");
+            }
+        };
+    }
+
+    @Test
+    void testStringBodyIsSignedAsUtf8() throws Exception {
+        resultSign.expectedMessageCount(1);
+        templateSign.sendBody(NON_ASCII);
+        resultSign.assertIsSatisfied();
+
+        byte[] signature = resultSign.getExchanges().get(0).getMessage().getHeader(PQCConstants.SIGNATURE, byte[].class);
+        assertNotNull(signature);
+
+        // The signature must validate against the UTF-8 bytes of the payload
+        assertTrue(verifyOver(NON_ASCII.getBytes(StandardCharsets.UTF_8), signature),
+                "a String body must be signed as UTF-8");
+        // ... and must not validate against a different encoding of the same non-ASCII text
+        assertFalse(verifyOver(NON_ASCII.getBytes(StandardCharsets.ISO_8859_1), signature),
+                "a String body must not be signed with the platform charset (ISO-8859-1 here)");
+    }
+
+    private boolean verifyOver(byte[] data, byte[] signature) throws Exception {
+        Signature verifier = Signature.getInstance(PQCSignatureAlgorithms.MLDSA.getAlgorithm(),
+                PQCSignatureAlgorithms.MLDSA.getBcProvider());
+        verifier.initVerify(keyPair.getPublic());
+        verifier.update(data);
+        return verifier.verify(signature);
+    }
+
+    @BindToRegistry("Keypair")
+    public KeyPair setKeyPair()
+            throws NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException {
+        KeyPairGenerator kpGen = KeyPairGenerator.getInstance(PQCSignatureAlgorithms.MLDSA.getAlgorithm(),
+                PQCSignatureAlgorithms.MLDSA.getBcProvider());
+        kpGen.initialize(MLDSAParameterSpec.ml_dsa_65);
+        keyPair = kpGen.generateKeyPair();
+        return keyPair;
+    }
+
+    @BindToRegistry("Signer")
+    public Signature getSigner() throws NoSuchAlgorithmException, NoSuchProviderException {
+        return Signature.getInstance(PQCSignatureAlgorithms.MLDSA.getAlgorithm(),
+                PQCSignatureAlgorithms.MLDSA.getBcProvider());
+    }
+}