diff -r 0aa5378d4f09 -r 8c2faee50bc4 src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java	Wed Aug 15 16:01:48 2018 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java	Wed Aug 15 13:39:32 2018 -0700
@@ -499,7 +499,8 @@
                 break;
 
             case BOUND:             /** Expr :: instMethod */
-                init = tree.getQualifierExpression();
+                init = transTypes.coerce(attrEnv, tree.getQualifierExpression(),
+                    types.erasure(tree.sym.owner.type));
                 init = attr.makeNullCheck(init);
                 break;