diff --git a/geowebcache/core/src/main/java/org/geowebcache/proxy/ProxyDispatcher.java b/geowebcache/core/src/main/java/org/geowebcache/proxy/ProxyDispatcher.java
index 09b4a608a..d21a86dba 100644
--- a/geowebcache/core/src/main/java/org/geowebcache/proxy/ProxyDispatcher.java
+++ b/geowebcache/core/src/main/java/org/geowebcache/proxy/ProxyDispatcher.java
@@ -43,7 +43,8 @@ protected ModelAndView handleRequestInternal(
             throw new ServletException("Expected url parameter.");
         }
 
-        synchronized (this) {
+        // lastRequest is static, static synchronization needed
+        synchronized (ProxyDispatcher.class) {
             long time = System.currentTimeMillis();
             if (time - lastRequest < 1000) {
                 throw new ServletException("Only one request per second please.");
diff --git a/geowebcache/pom.xml b/geowebcache/pom.xml
index b33df7650..f599f64e4 100644
--- a/geowebcache/pom.xml
+++ b/geowebcache/pom.xml
@@ -885,7 +885,7 @@
           <plugin>
             <groupId>com.github.spotbugs</groupId>
             <artifactId>spotbugs-maven-plugin</artifactId>
-            <version>4.0.0</version>
+            <version>4.7.3.4</version>
             <executions>
               <execution>
                 <goals>
@@ -894,12 +894,12 @@
               </execution>
             </executions>
             <configuration>
+              <fork>false</fork>
               <effort>More</effort>
               <!--threshold>High</threshold-->
               <xmlOutput>true</xmlOutput>
               <maxRank>15</maxRank>
               <excludeFilterFile>${geowebcacheBaseDir}/spotbugs-exclude.xml</excludeFilterFile>
-              <jvmArgs>-XX:+TieredCompilation -XX:TieredStopAtLevel=1</jvmArgs>
             </configuration>
           </plugin>
         </plugins>