diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index 4a7bf79b2..c01cde61a 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -64,9 +64,10 @@ void RTLIL::IdString::prepopulate()
 {
 	int size = static_cast<short>(RTLIL::StaticId::STATIC_ID_END);
 	global_id_storage_.reserve(size);
-	RTLIL::IdString::global_id_storage_.push_back({const_cast<char*>(""), 0});
 	global_id_index_.reserve(size);
 	global_refcount_storage_.resize(size, 1);
+	RTLIL::IdString::global_id_index_.insert({"", 0});
+	RTLIL::IdString::global_id_storage_.push_back({const_cast<char*>(""), 0});
 #define X(N) populate("\\" #N);
 #include "kernel/constids.inc"
 #undef X
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index d570e39a3..47ab6f06c 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -236,9 +236,6 @@ struct RTLIL::IdString
 
 		ensure_prepopulated();
 
-		if (p.empty())
-			return 0;
-
 		log_assert(p[0] == '$' || p[0] == '\\');
 		for (char ch : p)
 			if ((unsigned)ch <= (unsigned)' ')