diff --git a/brave/pom.xml b/brave/pom.xml
index 4570d173..5078ee0f 100644
--- a/brave/pom.xml
+++ b/brave/pom.xml
@@ -41,7 +41,17 @@
       <groupId>${project.groupId}</groupId>
       <artifactId>zipkin-reporter</artifactId>
       <version>${project.version}</version>
+      <!-- Exclude the Zipkin dependency by default because
+           AsyncZipkinSpanHandler avoids zipkin types. -->
+      <exclusions>
+        <exclusion>
+          <groupId>io.zipkin.zipkin2</groupId>
+          <artifactId>zipkin</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
+    <!-- Those using ZipkinSpanHandler.create or newBuilder need zipkin types
+         as they are passing a zipkin2.Span reporter. -->
     <dependency>
       <groupId>io.zipkin.zipkin2</groupId>
       <artifactId>zipkin</artifactId>
diff --git a/core/pom.xml b/core/pom.xml
index 73034a64..b422502f 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -37,11 +37,12 @@
   </properties>
 
   <dependencies>
+    <!-- This dependency can be excluded for those not using
+         zipkin2.reporter.AsyncReporter, which uses zipkin2 types. -->
     <dependency>
       <groupId>io.zipkin.zipkin2</groupId>
       <artifactId>zipkin</artifactId>
       <version>${zipkin.version}</version>
-      <optional>true</optional>
     </dependency>
   </dependencies>