diff --git a/security-jwt/build.gradle.kts b/security-jwt/build.gradle.kts
index f707a7c9ef..25e4d64177 100644
--- a/security-jwt/build.gradle.kts
+++ b/security-jwt/build.gradle.kts
@@ -15,6 +15,7 @@ dependencies {
     implementation(mnReactor.micronaut.reactor)
     compileOnly(mnCache.micronaut.cache.core)
     testImplementation(libs.bcpkix.jdk15on)
+    testImplementation(mnCache.micronaut.cache.caffeine)
 
     compileOnly(mn.micronaut.http.client.core)
     compileOnly(mn.micronaut.http.server)
@@ -38,6 +39,10 @@ dependencies {
     testImplementation(mnTestResources.testcontainers.core)
 
     testImplementation(libs.system.stubs.core)
+
+    testImplementation(mnTest.micronaut.test.junit5)
+    testImplementation(libs.junit.jupiter.params)
+    testRuntimeOnly(libs.junit.jupiter.engine)
 }
 
 tasks.test {
diff --git a/security-jwt/src/main/java/io/micronaut/security/token/jwt/signature/jwks/ReactorCacheJwkSetFetcher.java b/security-jwt/src/main/java/io/micronaut/security/token/jwt/signature/jwks/ReactorCacheJwkSetFetcher.java
index 1fbd8dbba4..dba3ac0084 100644
--- a/security-jwt/src/main/java/io/micronaut/security/token/jwt/signature/jwks/ReactorCacheJwkSetFetcher.java
+++ b/security-jwt/src/main/java/io/micronaut/security/token/jwt/signature/jwks/ReactorCacheJwkSetFetcher.java
@@ -62,10 +62,10 @@ public Publisher<JWKSet> fetch(@Nullable String providerName, @Nullable String u
     }
 
     private Mono<JwksCacheEntry> jwksCacheEntry(CacheKey cacheKey) {
-        return Mono.from(super.fetch(cacheKey.providerName, cacheKey.url()))
-                .defaultIfEmpty(new JWKSet())
-                .map(jwksSet -> instantiateCacheEntry(cacheKey, jwksSet))
-                .cacheInvalidateIf(JwksCacheEntry::isExpired);
+        return Mono.defer(() -> Mono.from(super.fetch(cacheKey.providerName, cacheKey.url())))
+            .defaultIfEmpty(new JWKSet())
+            .map(jwksSet -> instantiateCacheEntry(cacheKey, jwksSet))
+            .cacheInvalidateIf(JwksCacheEntry::isExpired);
     }
 
     private JwksCacheEntry instantiateCacheEntry(CacheKey cacheKey, JWKSet jwkSet) {
@@ -73,7 +73,7 @@ private JwksCacheEntry instantiateCacheEntry(CacheKey cacheKey, JWKSet jwkSet) {
                 ? jwksSignatureConfigurations.get(cacheKey.providerName).getCacheExpiration()
                 : JwksSignatureConfigurationProperties.DEFAULT_CACHE_EXPIRATION));
     }
-    
+
     private record CacheKey(String providerName, String url) {
     }
 
diff --git a/security-jwt/src/test/java/io/micronaut/security/token/jwt/signature/jwks/JwksRequestDoesNotDuplicateHeadersTest.java b/security-jwt/src/test/java/io/micronaut/security/token/jwt/signature/jwks/JwksRequestDoesNotDuplicateHeadersTest.java
new file mode 100644
index 0000000000..f762cd94df
--- /dev/null
+++ b/security-jwt/src/test/java/io/micronaut/security/token/jwt/signature/jwks/JwksRequestDoesNotDuplicateHeadersTest.java
@@ -0,0 +1,114 @@
+package io.micronaut.security.token.jwt.signature.jwks;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.http.HttpRequest;
+import io.micronaut.http.HttpResponse;
+import io.micronaut.http.MutableHttpRequest;
+import io.micronaut.http.annotation.Controller;
+import io.micronaut.http.annotation.Filter;
+import io.micronaut.http.annotation.Get;
+import io.micronaut.http.client.BlockingHttpClient;
+import io.micronaut.http.client.HttpClient;
+import io.micronaut.http.filter.ClientFilterChain;
+import io.micronaut.http.filter.HttpClientFilter;
+import io.micronaut.runtime.server.EmbeddedServer;
+import io.micronaut.security.annotation.Secured;
+import io.micronaut.security.rules.SecurityRule;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.reactivestreams.Publisher;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.params.provider.Arguments.arguments;
+
+class JwksRequestDoesNotDuplicateHeadersTest {
+    static Stream<Arguments> paramsProvider() {
+        return Stream.of(
+            arguments(CacheableJwkSetFetcher.class, "micronaut.caches.jwks.expire-after-write", "0s"),
+            arguments(ReactorCacheJwkSetFetcher.class, "micronaut.security.token.jwt.signatures.jwks.google.cache-expiration", "0"));
+    }
+
+    @ParameterizedTest
+    @MethodSource("paramsProvider")
+    void jwksRequestDoesNotDuplicateHeadersTest(Class fetcherClass, String configName, String configValue) {
+        Map<String, Object> authServerConfig = Map.of("spec.name", "JwksRequestDoesNotDuplicateHeadersTestGoogle");
+        try (EmbeddedServer authServer = ApplicationContext.run(EmbeddedServer.class, authServerConfig)) {
+            Map<String, Object> serverConfig = Map.of("spec.name", "JwksRequestDoesNotDuplicateHeadersTest",
+                "micronaut.http.client.read-timeout", "5m",
+                "micronaut.security.token.jwt.signatures.jwks.google.url",
+            "http://localhost:" + authServer.getPort() + "/oauth2/v3/certs",
+                configName, configValue);
+            try (EmbeddedServer server = ApplicationContext.run(EmbeddedServer.class, serverConfig)) {
+                assertInstanceOf(fetcherClass, server.getApplicationContext().getBean(JwkSetFetcher.class));
+                HttpClient httpClient = server.getApplicationContext().createBean(HttpClient.class, server.getURL());
+                BlockingHttpClient client = httpClient.toBlocking();
+                assertNotNull(client);
+                String jwt = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c";
+                int numberOfRequests = 5;
+                for (int i = 0; i < numberOfRequests; i++) {
+                    assertEquals("{\"message\":\"Hello World\"}", client.retrieve(HttpRequest.GET("/").bearerAuth(jwt)));
+                }
+                assertEquals(5, authServer.getApplicationContext().getBean(GoogleAuthController.class).headers.size());
+            }
+        }
+    }
+
+    @Requires(property = "spec.name", value = "JwksRequestDoesNotDuplicateHeadersTest")
+    @Controller
+    static class HomeController {
+
+        @Secured(SecurityRule.IS_ANONYMOUS)
+        @Get
+        Map<String, String> index() {
+            return Collections.singletonMap("message", "Hello World");
+        }
+    }
+
+    @Requires(property = "spec.name", value = "JwksRequestDoesNotDuplicateHeadersTest")
+    @Filter(patterns = "/oauth2/v3/certs")
+    static class AddHeaderFilter implements HttpClientFilter {
+        public Publisher<? extends HttpResponse<?>> doFilter(MutableHttpRequest<?> request, ClientFilterChain chain) {
+            return chain.proceed(request.header("hdr", "a really long string ..."));
+        }
+    }
+
+    @Requires(property = "spec.name", value = "JwksRequestDoesNotDuplicateHeadersTestGoogle")
+    @Controller
+    static class GoogleAuthController {
+        List<String> headers = new ArrayList<>();
+        @Secured(SecurityRule.IS_ANONYMOUS)
+        @Get("/oauth2/v3/certs")
+        String index(HttpRequest<?> request) {
+            headers.addAll(request.getHeaders().getAll("hdr"));
+            return """
+                {
+                  "keys": [
+                    {
+                      "kty": "RSA",
+                      "e": "AQAB",
+                      "use": "sig",
+                      "kid": "fa072f75784642615087c7182c101341e18f7a3a",
+                      "n": "pleuF0RyDsETygZn89RpGVFNMxG_hdYVnvbHadvM1tYxs9ghDq93NFxejt--1QlwpLQ3yuVY_CKldkAWgzPVl8-oUBe5xh9jzpLUTqcyrS1aFLuzAe13-OTadUE18wvhz9goQf80rg5IztD_gBePOOBE7eWHGqWLghuMb7cIYjgFxqNFyPn8bF_7k8pQAeHIPua_6_GHhw3ML4msp-aU7O1io3Z4P_Bir_6_C5J9UtWAcJ0Ez0YC5FxOMkh27joO5mUas8krGnFqIJTOgDYXQC1QTu-HOCRNvi6gFMqEkDTP5oBK2cDPDq5L0T8Q0UanSPR0BuOTHesCXnDAdxdyXw",
+                      "alg": "RS256"
+                    },
+                    {
+                      "n": "5D9Xb4z8eFr-3Zh3m5GnM_KVqc6rskPL7EMa6lSxNiMJ-PhXGORU-S-QgLmMvHu3vAMfvxz6ph3JZDpdGT68wj-vWqqBudaDYCbnbkjXm6UpcrFMpGAiOS6gACNxpz80JXaO2DPtl9jTN6WyJY9tLHdqRfesfOlwzB0lmVZ8shSDh8usN3vB1KfYuR6Vytly1phaWJr92yMICKUjtXT-0SlrtqDgX_U2Swl4QyZN6rrfuG3F6Fmw-m12Ve_kyoPUb02bbJCSFDnIZsMvRlSZem5nUrs86zDPTWfNcB0LUYG8OgMzOev7r04h_RY2F6K7c8nE2EobYTrH0kw2QIf8vQ",
+                      "alg": "RS256",
+                      "kid": "eec534fa5b8caca201ca8d0ff96b54c562210d1e",
+                      "e": "AQAB",
+                      "kty": "RSA",
+                      "use": "sig"
+                    }
+                  ]
+                }
+                """;
+        }
+    }
+}