diff --git a/stage0/parser.c b/stage0/parser.c
index 0ebdf05686..2c47bec424 100644
--- a/stage0/parser.c
+++ b/stage0/parser.c
@@ -2953,16 +2953,20 @@ static AstNodeIndex parseSwitchProng(Parser* p) {
     const AstTokenIndex arrow
         = expectToken(p, TOKEN_EQUAL_ANGLE_BRACKET_RIGHT);
     parsePtrPayload(p);
-    const AstNodeIndex case_body = parseAssignExpr(p);
-    if (case_body == 0) {
-        fail(p, "expected expression");
-    }
 
     const uint32_t items_len = p->scratch.len - items_old_len;
     AstNodeIndex case_node;
     switch (items_len) {
     case 0:
-    case 1:
+    case 1: {
+        // In Zig, .data fields are evaluated in order, so for
+        // switch_case_one, the items are in data[0] and the body
+        // (expectSingleAssignExpr) is in data[1]. Since items don't go
+        // through extra_data here, ordering doesn't matter.
+        const AstNodeIndex case_body = parseAssignExpr(p);
+        if (case_body == 0) {
+            fail(p, "expected expression");
+        }
         case_node = addNode(&p->nodes,
             (AstNodeItem) {
                 .tag = is_inline
@@ -2975,10 +2979,21 @@ static AstNodeIndex parseSwitchProng(Parser* p) {
                     .rhs = case_body,
                 },
             });
-        break;
+    } break;
     default: {
+        // In Zig, struct literal field init order is guaranteed:
+        //   data[0] = addExtra(listToSpan(items))  -- writes items to
+        //   extra_data first data[1] = expectSingleAssignExpr()      -- parses
+        //   body after
+        // We must maintain this order in C.
         const AstSubRange span
             = listToSpan(p, &p->scratch.arr[items_old_len], items_len);
+        const AstNodeIndex extra_idx
+            = addExtra(p, (AstNodeIndex[]) { span.start, span.end }, 2);
+        const AstNodeIndex case_body = parseAssignExpr(p);
+        if (case_body == 0) {
+            fail(p, "expected expression");
+        }
         case_node = addNode(&p->nodes,
             (AstNodeItem) {
                 .tag = is_inline
@@ -2986,8 +3001,7 @@ static AstNodeIndex parseSwitchProng(Parser* p) {
                     : AST_NODE_SWITCH_CASE,
                 .main_token = arrow,
                 .data = {
-                    .lhs = addExtra(p,
-                        (AstNodeIndex[]) { span.start, span.end }, 2),
+                    .lhs = extra_idx,
                     .rhs = case_body,
                 },
             });
diff --git a/stage0/stages_test.zig b/stage0/stages_test.zig
index f627ccd8fd..d3465fb4ff 100644
--- a/stage0/stages_test.zig
+++ b/stage0/stages_test.zig
@@ -30,50 +30,50 @@ const corpus_files = .{
     "../lib/c/inttypes.zig",
     "../lib/compiler/aro/aro/annex_g.zig",
     "../lib/compiler/aro/aro/Attribute/names.zig",
-    //"../lib/compiler/aro/aro/Attribute.zig",
+    "../lib/compiler/aro/aro/Attribute.zig",
     "../lib/compiler/aro/aro/Builtins/Builtin.zig",
-    //"../lib/compiler/aro/aro/Builtins/eval.zig",
+    "../lib/compiler/aro/aro/Builtins/eval.zig",
     "../lib/compiler/aro/aro/Builtins/Properties.zig",
-    //"../lib/compiler/aro/aro/Builtins/TypeDescription.zig",
+    "../lib/compiler/aro/aro/Builtins/TypeDescription.zig",
     "../lib/compiler/aro/aro/Builtins.zig",
     "../lib/compiler/aro/aro/char_info/identifier_tables.zig",
     //"../lib/compiler/aro/aro/char_info.zig",
-    //"../lib/compiler/aro/aro/CodeGen.zig",
-    //"../lib/compiler/aro/aro/Compilation.zig",
-    //"../lib/compiler/aro/aro/Diagnostics/messages.zig",
-    //"../lib/compiler/aro/aro/Diagnostics.zig",
-    //"../lib/compiler/aro/aro/Driver/Distro.zig",
-    //"../lib/compiler/aro/aro/Driver/Filesystem.zig",
-    //"../lib/compiler/aro/aro/Driver/GCCDetector.zig",
-    //"../lib/compiler/aro/aro/Driver/GCCVersion.zig",
-    //"../lib/compiler/aro/aro/Driver/Multilib.zig",
-    //"../lib/compiler/aro/aro/Driver.zig",
-    //"../lib/compiler/aro/aro/features.zig",
-    //"../lib/compiler/aro/aro/Hideset.zig",
-    //"../lib/compiler/aro/aro/InitList.zig",
-    //"../lib/compiler/aro/aro/LangOpts.zig",
-    //"../lib/compiler/aro/aro/Parser.zig",
-    //"../lib/compiler/aro/aro/pragmas/gcc.zig",
-    //"../lib/compiler/aro/aro/pragmas/message.zig",
-    //"../lib/compiler/aro/aro/pragmas/once.zig",
-    //"../lib/compiler/aro/aro/pragmas/pack.zig",
-    //"../lib/compiler/aro/aro/Pragma.zig",
-    //"../lib/compiler/aro/aro/Preprocessor.zig",
-    //"../lib/compiler/aro/aro/record_layout.zig",
-    //"../lib/compiler/aro/aro/Source.zig",
-    //"../lib/compiler/aro/aro/StringInterner.zig",
-    //"../lib/compiler/aro/aro/SymbolStack.zig",
-    //"../lib/compiler/aro/aro/target.zig",
-    //"../lib/compiler/aro/aro/text_literal.zig",
-    //"../lib/compiler/aro/aro/Tokenizer.zig",
-    //"../lib/compiler/aro/aro/toolchains/Linux.zig",
-    //"../lib/compiler/aro/aro/Toolchain.zig",
-    //"../lib/compiler/aro/aro/tracy.zig",
-    //"../lib/compiler/aro/aro/Tree/number_affixes.zig",
-    //"../lib/compiler/aro/aro/Tree.zig",
-    //"../lib/compiler/aro/aro/Type.zig",
-    //"../lib/compiler/aro/aro/Value.zig",
-    //"../lib/compiler/aro/aro.zig",
+    "../lib/compiler/aro/aro/CodeGen.zig",
+    "../lib/compiler/aro/aro/Compilation.zig",
+    "../lib/compiler/aro/aro/Diagnostics/messages.zig",
+    "../lib/compiler/aro/aro/Diagnostics.zig",
+    "../lib/compiler/aro/aro/Driver/Distro.zig",
+    "../lib/compiler/aro/aro/Driver/Filesystem.zig",
+    "../lib/compiler/aro/aro/Driver/GCCDetector.zig",
+    "../lib/compiler/aro/aro/Driver/GCCVersion.zig",
+    "../lib/compiler/aro/aro/Driver/Multilib.zig",
+    "../lib/compiler/aro/aro/Driver.zig",
+    "../lib/compiler/aro/aro/features.zig",
+    "../lib/compiler/aro/aro/Hideset.zig",
+    "../lib/compiler/aro/aro/InitList.zig",
+    "../lib/compiler/aro/aro/LangOpts.zig",
+    "../lib/compiler/aro/aro/Parser.zig",
+    "../lib/compiler/aro/aro/pragmas/gcc.zig",
+    "../lib/compiler/aro/aro/pragmas/message.zig",
+    "../lib/compiler/aro/aro/pragmas/once.zig",
+    "../lib/compiler/aro/aro/pragmas/pack.zig",
+    "../lib/compiler/aro/aro/Pragma.zig",
+    "../lib/compiler/aro/aro/Preprocessor.zig",
+    "../lib/compiler/aro/aro/record_layout.zig",
+    "../lib/compiler/aro/aro/Source.zig",
+    "../lib/compiler/aro/aro/StringInterner.zig",
+    "../lib/compiler/aro/aro/SymbolStack.zig",
+    "../lib/compiler/aro/aro/target.zig",
+    "../lib/compiler/aro/aro/text_literal.zig",
+    "../lib/compiler/aro/aro/Tokenizer.zig",
+    "../lib/compiler/aro/aro/toolchains/Linux.zig",
+    "../lib/compiler/aro/aro/Toolchain.zig",
+    "../lib/compiler/aro/aro/tracy.zig",
+    "../lib/compiler/aro/aro/Tree/number_affixes.zig",
+    "../lib/compiler/aro/aro/Tree.zig",
+    "../lib/compiler/aro/aro/Type.zig",
+    "../lib/compiler/aro/aro/Value.zig",
+    "../lib/compiler/aro/aro.zig",
     //"../lib/compiler/aro/backend/Interner.zig",
     //"../lib/compiler/aro/backend/Ir/x86/Renderer.zig",
     //"../lib/compiler/aro/backend/Ir.zig",