diff --git a/include/cpu.hpp b/include/cpu.hpp
index 9154a22..bf8f5fd 100644
--- a/include/cpu.hpp
+++ b/include/cpu.hpp
@@ -23,7 +23,7 @@ struct cpuSensors {
     uint32_t avg_freq = 0;
 };
 
-void detectHwmon(cpuSensors* target, std::string pci);
+void detectHwmon(cpuSensors* target, const std::string& pci);
 void update(cpuSensors* g);
 
 }  // namespace cpu
diff --git a/include/gpu.hpp b/include/gpu.hpp
index 1821f78..428407a 100644
--- a/include/gpu.hpp
+++ b/include/gpu.hpp
@@ -43,7 +43,7 @@ struct gpuSensors {
     // uint64_t vram_total = 0;
 };
 
-void detectHwmon(gpuSensors* target, std::string pci);
+void detectHwmon(gpuSensors* target, const std::string& pci);
 void update(gpuSensors* g);
 
 }  // namespace gpu
diff --git a/src/cpu.cpp b/src/cpu.cpp
index ee81f78..a69c1b6 100644
--- a/src/cpu.cpp
+++ b/src/cpu.cpp
@@ -7,7 +7,7 @@
 
 namespace cpu {
 
-void detectHwmon(cpuSensors* target, std::string pci) {
+void detectHwmon(cpuSensors* target, const std::string& pci) {
     std::string path = "/sys/bus/pci/devices/" + pci + "/hwmon";
 
     try {
diff --git a/src/gpu.cpp b/src/gpu.cpp
index 587b291..64db35f 100644
--- a/src/gpu.cpp
+++ b/src/gpu.cpp
@@ -10,7 +10,7 @@
 namespace gpu {
 
 /* takes pointer to a target gpu::sensors struct and updates its hwmon path and detects gpu_metrics */
-void detectHwmon(gpuSensors* target, std::string pci) {
+void detectHwmon(gpuSensors* target, const std::string& pci) {
     target->hwmon = getFirstDir("/sys/bus/pci/devices/" + pci + "/hwmon");
     log(LOG::INF, "gpu::detectHwmon", "Detected path \"{}\"", target->hwmon);