diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/UnnecessaryBoxedAssignment.java b/core/src/main/java/com/google/errorprone/bugpatterns/UnnecessaryBoxedAssignment.java
index 1aff9bdcf8a..a7aeecbde11 100644
--- a/core/src/main/java/com/google/errorprone/bugpatterns/UnnecessaryBoxedAssignment.java
+++ b/core/src/main/java/com/google/errorprone/bugpatterns/UnnecessaryBoxedAssignment.java
@@ -65,7 +65,8 @@ public Description matchVariable(VariableTree tree, VisitorState state) {
   }
 
   private Description matchCommon(ExpressionTree expression, VisitorState state) {
-    if (expression == null || !VALUE_OF_MATCHER.matches(expression, state)) {
+    if (!(expression instanceof MethodInvocationTree)
+        || !VALUE_OF_MATCHER.matches(expression, state)) {
       return Description.NO_MATCH;
     }
     MethodInvocationTree methodInvocationTree = (MethodInvocationTree) expression;
diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases.java b/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases.java
index 79009c45657..501a303e143 100644
--- a/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases.java
+++ b/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases.java
@@ -16,6 +16,8 @@
 
 package com.google.errorprone.bugpatterns.testdata;
 
+import java.util.function.Function;
+
 /**
  * @author awturner@google.com (Andy Turner)
  */
@@ -76,4 +78,8 @@ Integer positive_wrappedAgain(int aInteger) {
     a = Integer.valueOf(aInteger);
     return Integer.valueOf(a);
   }
+
+  void negative_methodReference() {
+    Function<String, Boolean> toBoolean = Boolean::valueOf;
+  }
 }
diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases_expected.java b/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases_expected.java
index 87216d4087c..fc3fd40fd30 100644
--- a/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases_expected.java
+++ b/core/src/test/java/com/google/errorprone/bugpatterns/testdata/UnnecessaryBoxedAssignmentCases_expected.java
@@ -16,6 +16,8 @@
 
 package com.google.errorprone.bugpatterns.testdata;
 
+import java.util.function.Function;
+
 /**
  * @author awturner@google.com (Andy Turner)
  */
@@ -76,4 +78,8 @@ Integer positive_wrappedAgain(int aInteger) {
     a = aInteger;
     return a;
   }
+
+  void negative_methodReference() {
+    Function<String, Boolean> toBoolean = Boolean::valueOf;
+  }
 }