diff --git a/build.gradle b/build.gradle
index 0dcaea17..700638be 100644
--- a/build.gradle
+++ b/build.gradle
@@ -32,7 +32,7 @@ buildscript {
 plugins {
     id 'java-library'
     id 'maven-publish'
-    id 'com.diffplug.spotless' version '6.25.0'
+    id 'com.diffplug.spotless' version '8.10.1'
 }
 
 repositories {
@@ -121,13 +121,23 @@ test {
     }
 }
 
+// Only wire the Eclipse JDT step when a spotless task is actually being run, so non-spotless
+// Gradle invocations (test, assemble) don't provision the formatter at configuration time.
+def runningSpotlessTask = gradle.startParameter.taskNames.any { it.toLowerCase(Locale.ROOT).contains('spotless') }
+
 spotless {
     java {
         removeUnusedImports()
         importOrder 'java', 'javax', 'org', 'com'
         licenseHeaderFile 'spotless.license.java'
 
-        eclipse().withP2Mirrors(Map.of("https://download.eclipse.org/", "https://ci.opensearch.org/")).configFile rootProject.file('.eclipseformat.xml')
+        // Pin 4.29 explicitly: spotless 8.10.0+ ships an embedded lockfile for it, so the
+        // formatter resolves from Maven Central through the mirror below instead of querying a
+        // P2 update site at configuration time. Keep withP2Mirrors so any non-lockfile fallback
+        // still hits the ci.opensearch.org mirror rather than the eclipse.org origin.
+        if (runningSpotlessTask) {
+            eclipse('4.29').withP2Mirrors(Map.of("https://download.eclipse.org/", "https://ci.opensearch.org/")).configFile rootProject.file('.eclipseformat.xml')
+        }
     }
 }