diff --git a/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/ApplicationInsightsAppenderClassFileTransformer.java b/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/ApplicationInsightsAppenderClassFileTransformer.java
index 140cb8cccf..02c245a862 100644
--- a/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/ApplicationInsightsAppenderClassFileTransformer.java
+++ b/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/ApplicationInsightsAppenderClassFileTransformer.java
@@ -27,6 +27,8 @@ public class ApplicationInsightsAppenderClassFileTransformer implements ClassFil
       UnshadedSdkPackageName.get() + "/log4j/v2/ApplicationInsightsAppender";
   private static final String UNSHADED_CLASS_NAME_LOG_4_JV_1_2 =
       UnshadedSdkPackageName.get() + "/log4j/v1_2/ApplicationInsightsAppender";
+  private static final String UNSHADED_CLASS_NAME_LOGBACK_LOGGING_EVENT =
+      UnshadedSdkPackageName.getLogbackPrefix() + "logback/classic/spi/ILoggingEvent";
 
   @Override
   @Nullable
@@ -73,7 +75,7 @@ public MethodVisitor visitMethod(
         @Nullable String[] exceptions) {
       MethodVisitor mv = cw.visitMethod(access, name, descriptor, signature, exceptions);
       if (name.equals("append")
-          && (descriptor.equals("(Lch/qos/logback/classic/spi/ILoggingEvent;)V")
+          && (descriptor.equals("(L" + UNSHADED_CLASS_NAME_LOGBACK_LOGGING_EVENT + ";)V")
               || descriptor.equals("(Lorg/apache/log4j/spi/LoggingEvent;)V")
               || descriptor.equals("(Lorg/apache/logging/log4j/core/LogEvent;)V"))) {
         // no-op the append() method
diff --git a/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/UnshadedSdkPackageName.java b/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/UnshadedSdkPackageName.java
index 8ecc5d7fed..c25fceb6aa 100644
--- a/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/UnshadedSdkPackageName.java
+++ b/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/UnshadedSdkPackageName.java
@@ -5,16 +5,23 @@
 
 public class UnshadedSdkPackageName {
 
-  // using constant here so that it will NOT get shaded
-  // IMPORTANT FOR THIS NOT TO BE FINAL (or private)
-  // OTHERWISE COMPILER COULD THEORETICALLY INLINE IT BELOW AND APPLY .substring(1)
-  // and then it WOULD be shaded
+  // using package-prefix constants here so that they will NOT get shaded
+  // IMPORTANT FOR THESE NOT TO BE FINAL (or private)
+  // OTHERWISE COMPILER COULD THEORETICALLY INLINE THEM BELOW AND APPLY .substring(1)
+  // and then they WOULD be shaded
   @SuppressWarnings("ConstantField") // field value intentionally mutable for specific use case
   static String ALMOST_PREFIX = "!com/microsoft/applicationinsights";
 
+  @SuppressWarnings("ConstantField") // field value intentionally mutable for specific use case
+  static String ALMOST_LOGBACK_PREFIX = "!ch/qos/";
+
   public static String get() {
     return ALMOST_PREFIX.substring(1);
   }
 
+  public static String getLogbackPrefix() {
+    return ALMOST_LOGBACK_PREFIX.substring(1);
+  }
+
   private UnshadedSdkPackageName() {}
 }
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index cd31a2fc51..06dad191a1 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -32,11 +32,11 @@ dependencies {
   // When updating, update above in plugins too
   implementation("com.diffplug.spotless:spotless-plugin-gradle:8.2.1")
   implementation("com.github.spotbugs.snom:spotbugs-gradle-plugin:6.4.8")
-  implementation("com.gradleup.shadow:shadow-gradle-plugin:8.3.9")
+  implementation("com.gradleup.shadow:shadow-gradle-plugin:9.3.2")
 
   implementation("org.owasp:dependency-check-gradle:12.2.0")
 
-  implementation("io.opentelemetry.instrumentation:gradle-plugins:2.19.0-alpha")
+  implementation("io.opentelemetry.instrumentation:gradle-plugins:2.26.1-alpha")
 
   implementation("net.ltgt.gradle:gradle-errorprone-plugin:4.3.0")
   implementation("net.ltgt.gradle:gradle-nullaway-plugin:3.0.0")
diff --git a/buildSrc/src/main/kotlin/ai.shadow-conventions.gradle.kts b/buildSrc/src/main/kotlin/ai.shadow-conventions.gradle.kts
index 35f12ccf56..c09a2528c3 100644
--- a/buildSrc/src/main/kotlin/ai.shadow-conventions.gradle.kts
+++ b/buildSrc/src/main/kotlin/ai.shadow-conventions.gradle.kts
@@ -5,11 +5,28 @@ plugins {
 }
 
 tasks.withType<ShadowJar>().configureEach {
-  mergeServiceFiles {
-    include("inst/META-INF/services/*")
-  }
+  mergeServiceFiles()
+  mergeServiceFiles("inst/META-INF/services")
 
   exclude("**/module-info.class")
+  exclude("META-INF/*.SF")
+  exclude("META-INF/*.DSA")
+  exclude("META-INF/*.RSA")
+  exclude("META-INF/maven/**")
+  exclude("META-INF/INDEX.LIST")
+
+  // Keep service loaders merged while deduplicating non-functional META-INF metadata.
+  eachFile {
+    if (path.startsWith("META-INF/") && !path.startsWith("META-INF/services/")) {
+      duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+    }
+  }
+  filesMatching("META-INF/services/**") {
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
+  }
+  filesMatching("inst/META-INF/services/**") {
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
+  }
 
   // Prevents conflict with other SLF4J instances. Important for premain.
   relocate("org.slf4j", "io.opentelemetry.javaagent.slf4j")
diff --git a/buildSrc/src/main/kotlin/ai.smoke-test-jar.gradle.kts b/buildSrc/src/main/kotlin/ai.smoke-test-jar.gradle.kts
index c4ea2e69dd..41f26020ba 100644
--- a/buildSrc/src/main/kotlin/ai.smoke-test-jar.gradle.kts
+++ b/buildSrc/src/main/kotlin/ai.smoke-test-jar.gradle.kts
@@ -15,13 +15,17 @@ val aiSmokeTest = extensions.getByType(AiSmokeTestExtension::class)
 tasks.named<ShadowJar>("shadowJar") {
   archiveClassifier.set("")
   mergeServiceFiles()
-  
+
+  filesMatching("META-INF/spring.factories") {
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
+  }
+
   // Properly merge spring.factories files from all dependencies
   // This is required for Spring Boot auto-configuration to work
   // Use PropertiesFileTransformer to merge duplicate keys instead of simple append
   transform(PropertiesFileTransformer::class.java) {
     paths = listOf("META-INF/spring.factories")
-    mergeStrategy = "append"
+    mergeStrategy = PropertiesFileTransformer.MergeStrategy.Append
   }
   
   // Set main class - can be overridden by individual projects via mainClassName property