diff --git a/core/src/main/java/com/google/googlejavaformat/java/JavaInputAstVisitor.java b/core/src/main/java/com/google/googlejavaformat/java/JavaInputAstVisitor.java
index ea967b3d8..8914c8ea2 100644
--- a/core/src/main/java/com/google/googlejavaformat/java/JavaInputAstVisitor.java
+++ b/core/src/main/java/com/google/googlejavaformat/java/JavaInputAstVisitor.java
@@ -3475,14 +3475,15 @@ private static boolean expressionsAreParallel(
 
   // General helper functions.
 
-  enum DeclarationKind {
+  /** Kind of declaration. */
+  protected enum DeclarationKind {
     NONE,
     FIELD,
     PARAMETER
   }
 
   /** Declare one variable or variable-like thing. */
-  int declareOne(
+  protected int declareOne(
       DeclarationKind kind,
       Direction annotationsDirection,
       Optional<ModifiersTree> modifiers,
diff --git a/core/src/main/java/com/google/googlejavaformat/java/java17/Java17InputAstVisitor.java b/core/src/main/java/com/google/googlejavaformat/java/java17/Java17InputAstVisitor.java
index 6818f4a03..a7b5dbc44 100644
--- a/core/src/main/java/com/google/googlejavaformat/java/java17/Java17InputAstVisitor.java
+++ b/core/src/main/java/com/google/googlejavaformat/java/java17/Java17InputAstVisitor.java
@@ -22,7 +22,6 @@
 import com.google.googlejavaformat.OpsBuilder;
 import com.google.googlejavaformat.OpsBuilder.BlankLineWanted;
 import com.google.googlejavaformat.java.JavaInputAstVisitor;
-import com.sun.source.tree.AnnotationTree;
 import com.sun.source.tree.BindingPatternTree;
 import com.sun.source.tree.BlockTree;
 import com.sun.source.tree.CaseLabelTree;
@@ -84,18 +83,18 @@ public Void visitBindingPattern(BindingPatternTree node, Void unused) {
 
   private void visitBindingPattern(ModifiersTree modifiers, Tree type, Name name) {
     builder.open(plusFour);
-    if (modifiers != null) {
-      List<AnnotationTree> annotations =
-          visitModifiers(modifiers, Direction.HORIZONTAL, Optional.empty());
-      visitAnnotations(annotations, BreakOrNot.NO, BreakOrNot.YES);
-    }
-    scan(type, null);
-    builder.breakOp(" ");
-    if (name.isEmpty()) {
-      token("_");
-    } else {
-      visit(name);
-    }
+    declareOne(
+        DeclarationKind.PARAMETER,
+        Direction.HORIZONTAL,
+        Optional.of(modifiers),
+        type,
+        name,
+        /* op= */ "",
+        /* equals= */ "",
+        /* initializer= */ Optional.empty(),
+        /* trailing= */ Optional.empty(),
+        /* receiverExpression= */ Optional.empty(),
+        /* typeWithDims= */ Optional.empty());
     builder.close();
   }
 
diff --git a/core/src/test/java/com/google/googlejavaformat/java/FormatterIntegrationTest.java b/core/src/test/java/com/google/googlejavaformat/java/FormatterIntegrationTest.java
index b31e7bb15..5fb356750 100644
--- a/core/src/test/java/com/google/googlejavaformat/java/FormatterIntegrationTest.java
+++ b/core/src/test/java/com/google/googlejavaformat/java/FormatterIntegrationTest.java
@@ -61,7 +61,8 @@ public class FormatterIntegrationTest {
               "I880",
               "Unnamed",
               "I981",
-              "StringTemplate")
+              "StringTemplate",
+              "I1020")
           .build();
 
   @Parameters(name = "{index}: {0}")
diff --git a/core/src/test/resources/com/google/googlejavaformat/java/testdata/I1020.input b/core/src/test/resources/com/google/googlejavaformat/java/testdata/I1020.input
new file mode 100644
index 000000000..8ff084265
--- /dev/null
+++ b/core/src/test/resources/com/google/googlejavaformat/java/testdata/I1020.input
@@ -0,0 +1,15 @@
+public sealed interface A {
+    record AA(Long a) implements A {}
+    record AAA(String b) implements A {}
+    static Long mySwitch(A a) {
+        switch (a) {
+            case AA(var aa) -> {
+                return aa;
+            }
+            case AAA(var b) -> {
+                return Long.parseLong(b);
+            }
+        }
+    }
+}
+
diff --git a/core/src/test/resources/com/google/googlejavaformat/java/testdata/I1020.output b/core/src/test/resources/com/google/googlejavaformat/java/testdata/I1020.output
new file mode 100644
index 000000000..21e4a5156
--- /dev/null
+++ b/core/src/test/resources/com/google/googlejavaformat/java/testdata/I1020.output
@@ -0,0 +1,16 @@
+public sealed interface A {
+  record AA(Long a) implements A {}
+
+  record AAA(String b) implements A {}
+
+  static Long mySwitch(A a) {
+    switch (a) {
+      case AA(var aa) -> {
+        return aa;
+      }
+      case AAA(var b) -> {
+        return Long.parseLong(b);
+      }
+    }
+  }
+}