diff --git a/lib/std/zig/ast.zig b/lib/std/zig/ast.zig
index 349ae914c4c54251673b28572d838b15d62ed1e4..1c9b4eb3c9428eceac9fb5cf88a4cdeea4e584a3 100644
--- a/lib/std/zig/ast.zig
+++ b/lib/std/zig/ast.zig
@@ -13,6 +13,7 @@ pub const Tree = struct {
     root_node: *Node.Root,
     arena_allocator: std.heap.ArenaAllocator,
     errors: ErrorList,
+    generated: bool = false,
 
     pub const TokenList = SegmentedList(Token, 64);
     pub const ErrorList = SegmentedList(Error, 0);
@@ -58,6 +59,8 @@ pub const Tree = struct {
             .line_start = start_index,
             .line_end = self.source.len,
         };
+        if (self.generated)
+            return loc;
         const token_start = token.start;
         for (self.source[start_index..]) |c, i| {
             if (i + start_index == token_start) {
diff --git a/src-self-hosted/translate_c.zig b/src-self-hosted/translate_c.zig
index 4fc70f3af860e05e480685c64f750335f6002d70..dee4135ea104d37688b7b6c70de5d7f97c06b918 100644
--- a/src-self-hosted/translate_c.zig
+++ b/src-self-hosted/translate_c.zig
@@ -249,6 +249,7 @@ pub fn translate(
             .arena_allocator = tree_arena,
             .tokens = undefined, // can't reference the allocator yet
             .errors = undefined, // can't reference the allocator yet
+            .generated = true,
         };
         break :blk tree;
     };