diff a/src/java.base/macosx/classes/jdk/internal/sys/in6_h$constants.java b/src/java.base/macosx/classes/jdk/internal/sys/in6_h$constants.java
--- /dev/null
+++ b/src/java.base/macosx/classes/jdk/internal/sys/in6_h$constants.java
@@ -0,0 +1,55 @@
+// Generatable but for now somewhat handcrafted to encapsulate the layouts
+// generated by JStruct, with some additional memory handles and accessors to
+// mirror that of the what jextract generates as dynamic constants.
+package jdk.internal.sys;
+
+import jdk.incubator.foreign.MemoryLayout;
+import jdk.incubator.foreign.MemoryLayout.PathElement;
+import jdk.incubator.foreign.MemoryLayouts;
+import java.lang.invoke.VarHandle;
+
+final class in6_h$constants {
+
+    private static final MemoryLayout Cin6_addr$LAYOUT = MemoryLayout.ofStruct(
+            MemoryLayout.ofUnion(
+                    MemoryLayout.ofSequence(16, MemoryLayouts.BITS_8_LE).withName("__u6_addr8"),
+                    MemoryLayout.ofSequence(8, MemoryLayouts.BITS_16_LE).withName("__u6_addr16"),
+                    MemoryLayout.ofSequence(4, MemoryLayouts.BITS_32_LE).withName("__u6_addr32")
+            ).withName("__u6_addr")
+    ).withName("in6_addr");
+    static final MemoryLayout Cin6_addr$LAYOUT() {
+        return  Cin6_addr$LAYOUT;
+    }
+
+    private static final MemoryLayout Csockaddr_in6$LAYOUT = MemoryLayout.ofStruct(
+            MemoryLayouts.BITS_8_LE.withName("sin6_len"),
+            MemoryLayouts.BITS_8_LE.withName("sin6_family"),
+            MemoryLayouts.BITS_16_BE.withName("sin6_port"),
+            MemoryLayouts.BITS_32_LE.withName("sin6_flowinfo"),
+            Cin6_addr$LAYOUT,
+            MemoryLayouts.BITS_32_LE.withName("sin6_scope_id")
+    ).withName("sockaddr_in6");
+    private static final VarHandle sin6_len$VH = Csockaddr_in6$LAYOUT.varHandle(byte.class, PathElement.groupElement("sin6_len"));
+    private static final VarHandle sin6_family$VH = Csockaddr_in6$LAYOUT.varHandle(byte.class, PathElement.groupElement("sin6_family"));
+    private static final VarHandle sin6_port$VH = Csockaddr_in6$LAYOUT.varHandle(short.class, PathElement.groupElement("sin6_port"));
+    private static final VarHandle sin6_flowinfo$VH = Csockaddr_in6$LAYOUT.varHandle(int.class, PathElement.groupElement("sin6_flowinfo"));
+    private static final VarHandle sin6_scope_id$VH = Csockaddr_in6$LAYOUT.varHandle(int.class, PathElement.groupElement("sin6_scope_id"));
+    static final MemoryLayout Csockaddr_in6$LAYOUT() {
+        return Csockaddr_in6$LAYOUT;
+    }
+    static final VarHandle sin6_len$VH() {
+        return sin6_len$VH;
+    }
+    static final VarHandle sin6_family$VH() {
+        return sin6_family$VH;
+    }
+    static final VarHandle sin6_port$VH() {
+        return sin6_port$VH;
+    }
+    static final VarHandle sin6_flowinfo$VH() {
+        return sin6_flowinfo$VH;
+    }
+    static final VarHandle sin6_scope_id$VH() {
+        return sin6_scope_id$VH;
+    }
+}