diff --git a/.tav.yml b/.tav.yml
index 70a079d03f..bddc350dea 100644
--- a/.tav.yml
+++ b/.tav.yml
@@ -505,10 +505,16 @@ aws-sdk:
 # - In undici@4.7.1 the `request.origin` property was added, which we need
 #   in the 'undici:request:create' diagnostic message.
 undici:
-  versions: '4.7.1 || 4.10.4 || 5.1.1 || 5.12.0 || 5.22.0 || 5.27.1 || ^5.28.2'
-  commands: node test/instrumentation/modules/undici/undici.test.js
-  # Test v4.7.1, latest v5 and 5 versions in between.
-  update-versions:
-    mode: max-5
-    include: '>=4.7.1 <6'
+  - versions: '^6.0.0'
+    node: '>=18'
+    commands: node test/instrumentation/modules/undici/undici.test.js
+    update-versions:
+      mode: max-5
+      include: '>=6.0.0 <7'
+  - versions: '4.7.1 || 4.10.4 || 5.1.1 || 5.12.0 || 5.22.0 || 5.27.1 || ^5.28.2'
+    commands: node test/instrumentation/modules/undici/undici.test.js
+    # Test v4.7.1, latest v5 and 5 versions in between.
+    update-versions:
+      mode: max-5
+      include: '>=4.7.1 <6'
 
diff --git a/package-lock.json b/package-lock.json
index 4c1cc24218..4a53741319 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -128,7 +128,7 @@
         "thunky": "^1.1.0",
         "tree-kill": "^1.2.2",
         "typescript": "^5.0.2",
-        "undici": "^5.8.0",
+        "undici": "^6.2.1",
         "vasync": "^2.2.0",
         "wait-on": "^7.0.1",
         "ws": "^7.2.1"
@@ -4292,6 +4292,18 @@
       "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
       "dev": true
     },
+    "node_modules/@elastic/transport/node_modules/undici": {
+      "version": "5.28.2",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.2.tgz",
+      "integrity": "sha512-wh1pHJHnUeQV5Xa8/kyQhO7WFa8M34l026L5P/+2TYiakvGy5Rdc8jWZVyG7ieht/0WgJLEd3kcU5gKx+6GC8w==",
+      "dev": true,
+      "dependencies": {
+        "@fastify/busboy": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=14.0"
+      }
+    },
     "node_modules/@eslint-community/eslint-utils": {
       "version": "4.4.0",
       "resolved": "https://registry.npmjs.org/@eslint-community/eslint-utils/-/eslint-utils-4.4.0.tgz",
@@ -17607,15 +17619,15 @@
       }
     },
     "node_modules/undici": {
-      "version": "5.28.2",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.2.tgz",
-      "integrity": "sha512-wh1pHJHnUeQV5Xa8/kyQhO7WFa8M34l026L5P/+2TYiakvGy5Rdc8jWZVyG7ieht/0WgJLEd3kcU5gKx+6GC8w==",
+      "version": "6.2.1",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-6.2.1.tgz",
+      "integrity": "sha512-7Wa9thEM6/LMnnKtxJHlc8SrTlDmxqJecgz1iy8KlsN0/iskQXOQCuPkrZLXbElPaSw5slFFyKIKXyJ3UtbApw==",
       "dev": true,
       "dependencies": {
         "@fastify/busboy": "^2.0.0"
       },
       "engines": {
-        "node": ">=14.0"
+        "node": ">=18.0"
       }
     },
     "node_modules/undici-types": {
@@ -21463,6 +21475,15 @@
           "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
           "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
           "dev": true
+        },
+        "undici": {
+          "version": "5.28.2",
+          "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.2.tgz",
+          "integrity": "sha512-wh1pHJHnUeQV5Xa8/kyQhO7WFa8M34l026L5P/+2TYiakvGy5Rdc8jWZVyG7ieht/0WgJLEd3kcU5gKx+6GC8w==",
+          "dev": true,
+          "requires": {
+            "@fastify/busboy": "^2.0.0"
+          }
         }
       }
     },
@@ -31890,9 +31911,9 @@
       "dev": true
     },
     "undici": {
-      "version": "5.28.2",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.2.tgz",
-      "integrity": "sha512-wh1pHJHnUeQV5Xa8/kyQhO7WFa8M34l026L5P/+2TYiakvGy5Rdc8jWZVyG7ieht/0WgJLEd3kcU5gKx+6GC8w==",
+      "version": "6.2.1",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-6.2.1.tgz",
+      "integrity": "sha512-7Wa9thEM6/LMnnKtxJHlc8SrTlDmxqJecgz1iy8KlsN0/iskQXOQCuPkrZLXbElPaSw5slFFyKIKXyJ3UtbApw==",
       "dev": true,
       "requires": {
         "@fastify/busboy": "^2.0.0"
diff --git a/package.json b/package.json
index de39da8d01..91d318238d 100644
--- a/package.json
+++ b/package.json
@@ -206,7 +206,7 @@
     "thunky": "^1.1.0",
     "tree-kill": "^1.2.2",
     "typescript": "^5.0.2",
-    "undici": "^5.8.0",
+    "undici": "^6.2.1",
     "vasync": "^2.2.0",
     "wait-on": "^7.0.1",
     "ws": "^7.2.1"
diff --git a/test/_is_undici_incompat.js b/test/_is_undici_incompat.js
index 1cfaafd5db..f2ac0a9da7 100644
--- a/test/_is_undici_incompat.js
+++ b/test/_is_undici_incompat.js
@@ -6,7 +6,7 @@
 
 'use strict';
 
-var semver = require('semver');
+const { satisfies } = require('semver');
 
 /**
  * Return whether the current 'undici' version is incompatible with the
@@ -29,9 +29,11 @@ function isUndiciIncompat() {
   const undiciVer = require('undici/package.json').version;
   const msg = `undici@${undiciVer} is incompatible with node@${nodeVer}`;
 
-  if (
-    semver.satisfies(undiciVer, '>=5.28.0') &&
-    semver.satisfies(nodeVer, '<14.18.0')
+  if (satisfies(undiciVer, '>=6.0.0') && satisfies(nodeVer, '<18.0.0')) {
+    return msg;
+  } else if (
+    satisfies(undiciVer, '>=5.28.0') &&
+    satisfies(nodeVer, '<14.18.0')
   ) {
     return msg;
   }