diff --git a/src/Autodoc.zig b/src/Autodoc.zig
index b0ea618e70..e9fb8ab630 100644
--- a/src/Autodoc.zig
+++ b/src/Autodoc.zig
@@ -2594,12 +2594,12 @@ fn walkInstruction(
 
                     // We delay analysis because union tags can refer to
                     // decls defined inside the union itself.
-                    const tag_type_ref: Ref = if (small.has_tag_type) blk: {
+                    const tag_type_ref: ?Ref = if (small.has_tag_type) blk: {
                         const tag_type = file.zir.extra[extra_index];
                         extra_index += 1;
                         const tag_ref = @intToEnum(Ref, tag_type);
                         break :blk tag_ref;
-                    } else .none;
+                    } else null;
 
                     const body_len = if (small.has_body_len) blk: {
                         const body_len = file.zir.extra[extra_index];
@@ -2626,13 +2626,13 @@ fn walkInstruction(
                     );
 
                     // Analyze the tag once all decls have been analyzed
-                    const tag_type = try self.walkRef(
+                    const tag_type = if (tag_type_ref) |tt_ref| (try self.walkRef(
                         file,
                         &scope,
                         parent_src,
-                        tag_type_ref,
+                        tt_ref,
                         false,
-                    );
+                    )).expr else null;
 
                     // Fields
                     extra_index += body_len;
@@ -2664,7 +2664,7 @@ fn walkInstruction(
                             .privDecls = priv_decl_indexes.items,
                             .pubDecls = decl_indexes.items,
                             .fields = field_type_refs.items,
-                            .tag = tag_type.expr,
+                            .tag = tag_type,
                             .auto_enum = small.auto_enum_tag,
                             .parent_container = parent_scope.enclosing_type,
                         },
@@ -2855,6 +2855,9 @@ fn walkInstruction(
                         break :blk fields_len;
                     } else 0;
 
+                    // We don't care about decls yet
+                    if (small.has_decls_len) extra_index += 1;
+
                     var backing_int: ?DocData.Expr = null;
                     if (small.has_backing_int) {
                         const backing_int_body_len = file.zir.extra[extra_index];