diff --git a/activemq-client/pom.xml b/activemq-client/pom.xml
index 963d32f8..b822e02c 100644
--- a/activemq-client/pom.xml
+++ b/activemq-client/pom.xml
@@ -37,8 +37,8 @@
 
     <!-- CI should run the "release" profile during tests to ensure no 1.8
          features are in use. -->
-    <main.java.version>1.8</main.java.version>
-    <main.signature.artifact>java18</main.signature.artifact>
+    <!-- activemq is Java 1.6 bytecode -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -68,7 +68,6 @@
       <properties>
         <!-- activemq is Java 1.6 bytecode -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/amqp-client/pom.xml b/amqp-client/pom.xml
index 9eb9c1e0..94eeff48 100644
--- a/amqp-client/pom.xml
+++ b/amqp-client/pom.xml
@@ -34,6 +34,9 @@
     <amqp-client.version>5.20.0</amqp-client.version>
     <!-- Last pre-1.8 version -->
     <old-amqp-client.version>4.12.0</old-amqp-client.version>
+
+    <!-- amqp-client 4.x is Java 1.6 bytecode -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -95,7 +98,6 @@
       <properties>
         <!-- amqp-client 4.x is Java 1.6 bytecode -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/benchmarks/src/main/java/zipkin2/reporter/amqp/RabbitMQSenderBenchmarks.java b/benchmarks/src/main/java/zipkin2/reporter/amqp/RabbitMQSenderBenchmarks.java
index fdf64f33..f6f7fbb0 100644
--- a/benchmarks/src/main/java/zipkin2/reporter/amqp/RabbitMQSenderBenchmarks.java
+++ b/benchmarks/src/main/java/zipkin2/reporter/amqp/RabbitMQSenderBenchmarks.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 The OpenZipkin Authors
+ * Copyright 2016-2023 The OpenZipkin Authors
  *
  * Licensed 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
@@ -16,7 +16,6 @@
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.DefaultConsumer;
 import java.io.IOException;
-import org.junit.AssumptionViolatedException;
 import org.openjdk.jmh.runner.Runner;
 import org.openjdk.jmh.runner.RunnerException;
 import org.openjdk.jmh.runner.options.Options;
@@ -35,7 +34,7 @@ public class RabbitMQSenderBenchmarks extends SenderBenchmarks {
 
     CheckResult check = result.check();
     if (!check.ok()) {
-      throw new AssumptionViolatedException(check.error().getMessage(), check.error());
+      throw new IllegalStateException(check.error().getMessage(), check.error());
     }
 
     channel = result.localChannel();
diff --git a/brave/pom.xml b/brave/pom.xml
index bebac867..5a0c15ff 100644
--- a/brave/pom.xml
+++ b/brave/pom.xml
@@ -31,6 +31,9 @@
     <module.name>zipkin2.reporter.brave</module.name>
 
     <main.basedir>${project.basedir}/..</main.basedir>
+
+    <!-- The brave jar needs to be Java 1.6 bytecode -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -73,7 +76,6 @@
       <properties>
         <!-- The brave jar needs to be Java 1.6 bytecode -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/core/pom.xml b/core/pom.xml
index e7533951..c26b9377 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -31,6 +31,9 @@
     <module.name>zipkin2.reporter</module.name>
 
     <main.basedir>${project.basedir}/..</main.basedir>
+
+    <!-- The core jar needs to be Java 1.6 bytecode -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -47,7 +50,6 @@
       <properties>
         <!-- The core jar needs to be Java 1.6 bytecode -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/kafka/pom.xml b/kafka/pom.xml
index 8bbb4966..1aca2878 100644
--- a/kafka/pom.xml
+++ b/kafka/pom.xml
@@ -31,6 +31,9 @@
     <module.name>zipkin2.reporter.kafka</module.name>
 
     <main.basedir>${project.basedir}/..</main.basedir>
+
+    <!-- Kafka 0.11+ is Java 1.7 bytecode -->
+    <main.signature.artifact>java17</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -61,7 +64,6 @@
       <properties>
         <!-- Kafka 0.11+ is Java 1.7 bytecode -->
         <main.java.version>1.7</main.java.version>
-        <main.signature.artifact>java17</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/libthrift/pom.xml b/libthrift/pom.xml
index c53acdb6..28367c68 100644
--- a/libthrift/pom.xml
+++ b/libthrift/pom.xml
@@ -31,6 +31,9 @@
     <module.name>zipkin2.reporter.libthrift</module.name>
 
     <main.basedir>${project.basedir}/..</main.basedir>
+
+    <!-- Libthrift is Java 1.6 bytecode -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -72,7 +75,6 @@
       <properties>
         <!-- Libthrift is Java 1.6 bytecode -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/okhttp3/pom.xml b/okhttp3/pom.xml
index d80ed115..4e7d134e 100644
--- a/okhttp3/pom.xml
+++ b/okhttp3/pom.xml
@@ -33,6 +33,9 @@
     <main.basedir>${project.basedir}/..</main.basedir>
     <!-- pre-1.8, pre-kotlin, and last version before Call.timeout. -->
     <old-okhttp.version>3.11.0</old-okhttp.version>
+
+    <!-- OkHttp 3.x is Java 1.7 bytecode -->
+    <main.signature.artifact>java17</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -102,7 +105,6 @@
       <properties>
         <!-- OkHttp 3.x is Java 1.7 bytecode -->
         <main.java.version>1.7</main.java.version>
-        <main.signature.artifact>java17</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/pom.xml b/pom.xml
index 8f651194..e8409b6d 100755
--- a/pom.xml
+++ b/pom.xml
@@ -396,6 +396,8 @@
         </configuration>
         <executions>
           <execution>
+            <id>animal-sniffer</id>
+            <phase>verify</phase>
             <goals>
               <goal>check</goal>
             </goals>
diff --git a/spring-beans/pom.xml b/spring-beans/pom.xml
index f669e1ce..5f297105 100644
--- a/spring-beans/pom.xml
+++ b/spring-beans/pom.xml
@@ -31,6 +31,9 @@
     <module.name>zipkin2.reporter.beans</module.name>
 
     <main.basedir>${project.basedir}/..</main.basedir>
+
+    <!-- floor Java version we support for Spring 2.5 is 1.6 -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencyManagement>
@@ -120,7 +123,6 @@
       <properties>
         <!-- floor Java version we support for Spring 2.5 is 1.6 -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>
diff --git a/urlconnection/pom.xml b/urlconnection/pom.xml
index 7b41dfa2..3ad7142f 100644
--- a/urlconnection/pom.xml
+++ b/urlconnection/pom.xml
@@ -31,6 +31,9 @@
     <module.name>zipkin2.reporter.urlconnection</module.name>
 
     <main.basedir>${project.basedir}/..</main.basedir>
+
+    <!-- floor Java version we support for urlconnection is 1.6 -->
+    <main.signature.artifact>java16</main.signature.artifact>
   </properties>
 
   <dependencies>
@@ -54,7 +57,6 @@
       <properties>
         <!-- floor Java version we support for urlconnection is 1.6 -->
         <main.java.version>1.6</main.java.version>
-        <main.signature.artifact>java16</main.signature.artifact>
       </properties>
       <build>
         <plugins>