diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java
index 6fb1feed08d..e24b331dd63 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java
@@ -873,11 +873,10 @@ public class ThisEscapeAnalyzer extends TreeScanner {
 
     @Override
     public void visitAssign(JCAssign tree) {
-        VarSymbol sym = (VarSymbol)TreeInfo.symbolFor(tree.lhs);
         scan(tree.lhs);
         refs.discardExprs(depth);
         scan(tree.rhs);
-        if (isParamOrVar(sym))
+        if (TreeInfo.symbolFor(tree.lhs) instanceof VarSymbol sym && isParamOrVar(sym))
             refs.replaceExprs(depth, ref -> new VarRef(sym, ref));
         else
             refs.discardExprs(depth);         // we don't track fields yet
diff --git a/test/langtools/tools/javac/recovery/AttrRecovery.java b/test/langtools/tools/javac/recovery/AttrRecovery.java
index 64aaad2a184..fb852b5b3f2 100644
--- a/test/langtools/tools/javac/recovery/AttrRecovery.java
+++ b/test/langtools/tools/javac/recovery/AttrRecovery.java
@@ -23,7 +23,7 @@
 
 /*
  * @test
- * @bug 8301580 8322159 8333107 8332230 8338678 8351260 8366196 8372336 8373094 8384229
+ * @bug 8301580 8322159 8333107 8332230 8338678 8351260 8366196 8372336 8373094 8384229 8387865
  * @summary Verify error recovery w.r.t. Attr
  * @library /tools/lib
  * @modules jdk.compiler/com.sun.tools.javac.api
@@ -860,6 +860,33 @@ public class AttrRecovery {
                 .writeAll();
     }
 
+    @Test //JDK-8387865
+    public void testThisEscapeUnknownField() throws Exception {
+        String code = """
+                      public class C {
+                          public C() {
+                              this.unknown = unknown;
+                          }
+                      }
+                      """;
+        List<String> actual = new JavacTask(tb)
+                .options("-XDrawDiagnostics", "-XDdev",
+                         "-XDshould-stop.at=WARN", "-Xlint:this-escape")
+                .sources(code)
+                .outdir(base)
+                .run(Expect.FAIL)
+                .writeAll()
+                .getOutputLines(OutputKind.DIRECT);
+
+        List<String> expected = List.of(
+                "C.java:3:13: compiler.err.cant.resolve: kindname.variable, unknown, , ",
+                "C.java:3:24: compiler.err.cant.resolve.location: kindname.variable, unknown, , , (compiler.misc.location: kindname.class, C, null)",
+                "2 errors"
+        );
+
+        assertEquals(expected, actual);
+    }
+
     @BeforeEach
     public void setUp(TestInfo info) throws IOException {
         base = Path.of(info.getTestMethod().orElseThrow().getName());