--- old/src/jdk.jextract/share/classes/com/sun/tools/jextract/HeaderFile.java	2018-03-28 22:48:10.000000000 +0530
+++ new/src/jdk.jextract/share/classes/com/sun/tools/jextract/HeaderFile.java	2018-03-28 22:48:09.000000000 +0530
@@ -112,6 +112,20 @@
                     ctx.err.println(Main.format("warn.symbol.not.found", name));
                 }
             }
+
+            // C structs and unions can have nested structs, unions and enums.
+            if (c.kind() == CursorKind.StructDecl ||
+                c.kind() == CursorKind.UnionDecl) {
+                c.children()
+                    .filter(c1 -> c1.isDeclaration() &&
+                        (c1.kind() == CursorKind.StructDecl ||
+                        c1.kind() == CursorKind.UnionDecl ||
+                        c1.kind() == CursorKind.EnumDecl))
+                    .peek(c1 -> logger.finest(
+                        () -> "Cursor: " + c1.spelling() + "@" + c1.USR() + "?" + c1.isDeclaration()))
+                    .forEach(c1 -> processCursor(c1, main, isBuiltIn));
+            }
+
             JType jt = dict.computeIfAbsent(t, type -> {
                 logger.fine(() -> "PH: Compute type for " + type.spelling());
                 return define(type);