diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsage.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsage.java
index 278920247ca..7754ca540ca 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsage.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsage.java
@@ -19,7 +19,6 @@
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
-import com.google.errorprone.bugpatterns.BugChecker.MemberReferenceTreeMatcher;
 import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
 import com.google.errorprone.fixes.SuggestedFixes;
 import com.google.errorprone.matchers.Description;
@@ -27,10 +26,8 @@
 import com.google.errorprone.suppliers.Supplier;
 import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ExpressionTree;
-import com.sun.source.tree.MemberReferenceTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.tools.javac.code.Type;
-import com.sun.tools.javac.util.List;
 import reactor.core.publisher.Mono;
 
 /**
@@ -41,9 +38,10 @@
  * of the empty publisher and prematurely terminates the reactive chain from the execution. In most
  * cases this is not the desired behaviour.
  *
- * <p>NB: Mono&lt;?>#zipWith(Mono&lt;Void>) is allowed be the Reactor API, but it is an incorrect
- * usage of the API. It will be flagged by ErrorProne but the fix won't be supplied. The problem
- * with the original code should be revisited and fixed in a structural manner by the developer.
+ * <p>NB: Mono&lt;?&gt;#zipWith(Mono&lt;Void&gt;) is allowed be the Reactor API, but it is an
+ * incorrect usage of the API. It will be flagged by ErrorProne but the fix won't be supplied. The
+ * problem with the original code should be revisited and fixed in a structural manner by the
+ * developer.
  */
 @AutoService(BugChecker.class)
 @BugPattern(
@@ -55,7 +53,7 @@
     severity = ERROR,
     tags = LIKELY_ERROR)
 public final class MonoZipOfMonoVoidUsage extends BugChecker
-    implements MethodInvocationTreeMatcher, MemberReferenceTreeMatcher {
+    implements MethodInvocationTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final Supplier<Type> MONO = type(Mono.class.getName());
   // Mono.empty() yields `Mono<Object>` under the hood
@@ -111,17 +109,6 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
         .build();
   }
 
-  @Override
-  public Description matchMemberReference(MemberReferenceTree tree, VisitorState state) {
-    boolean dynamicMono = MONO_ZIP_AND_WITH.matches(tree, state);
-    boolean staticMono = STATIC_MONO_ZIP.matches(tree, state);
-
-    if (!dynamicMono && !staticMono) {
-      return Description.NO_MATCH;
-    }
-    return describeMatch(tree);
-  }
-
   private static Matcher<MethodInvocationTree> hasArgumentOfType(Supplier<Type> type) {
     return hasArgumentOfTypes(ImmutableList.of(type));
   }
@@ -149,12 +136,7 @@ private static Matcher<MethodInvocationTree> hasArgumentOfTypes(
         tree.getArguments().stream()
             .anyMatch(
                 arg -> {
-                  List<Type> allParams = ASTHelpers.getType(arg).allparams();
-                  if (allParams.isEmpty()) {
-                    return false;
-                  }
-
-                  Type argumentType = allParams.get(0);
+                  Type argumentType = ASTHelpers.getType(arg).allparams().get(0);
                   return types.stream()
                       .map(type -> type.get(state).allparams().get(0))
                       .anyMatch(