diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc
index 473918264..fd9986144 100644
--- a/backends/verilog/verilog_backend.cc
+++ b/backends/verilog/verilog_backend.cc
@@ -38,7 +38,7 @@ USING_YOSYS_NAMESPACE
 
 using namespace VERILOG_BACKEND;
 
-const pool<string> VERILOG_BACKEND::verilog_keywords() {
+const pool<string> &VERILOG_BACKEND::verilog_keywords() {
 	static const pool<string> res = {
 		// IEEE 1800-2017 Annex B
 		"accept_on", "alias", "always", "always_comb", "always_ff", "always_latch", "and", "assert", "assign", "assume", "automatic", "before",
diff --git a/backends/verilog/verilog_backend.h b/backends/verilog/verilog_backend.h
index 7e550a37c..affad995b 100644
--- a/backends/verilog/verilog_backend.h
+++ b/backends/verilog/verilog_backend.h
@@ -29,7 +29,7 @@
 YOSYS_NAMESPACE_BEGIN
 namespace VERILOG_BACKEND {
 
-    const pool<string> verilog_keywords();
+    const pool<string> &verilog_keywords();
     bool char_is_verilog_escaped(char c);
     bool id_is_verilog_escaped(const std::string &str);