diff --git a/.gitignore b/.gitignore
index 17a84ce..f74d71c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 gpufetch
+build/
diff --git a/src/common/main.cpp b/src/common/main.cpp
index f0b16af..2561966 100644
--- a/src/common/main.cpp
+++ b/src/common/main.cpp
@@ -71,6 +71,11 @@ int main(int argc, char* argv[]) {
 
   set_log_level(verbose_enabled());
 
+  int idx = get_gpu_idx();
+  if(!gpu_idx_valid(idx)) {
+    return EXIT_FAILURE;
+  }
+
   struct gpu_list* list = get_gpu_list();
   if(list_gpus()) {
     return print_gpus_list(list);
@@ -86,7 +91,7 @@ int main(int argc, char* argv[]) {
     return EXIT_FAILURE;
   }
 
-  struct gpu_info* gpu = get_gpu_info(list, get_gpu_idx());
+  struct gpu_info* gpu = get_gpu_info(list, idx);
   if(gpu == NULL)
     return EXIT_FAILURE;
 
diff --git a/src/common/master.cpp b/src/common/master.cpp
index b78ccc6..2a65a2d 100644
--- a/src/common/master.cpp
+++ b/src/common/master.cpp
@@ -5,6 +5,7 @@
 #include "global.hpp"
 #include "colors.hpp"
 #include "master.hpp"
+#include "args.hpp"
 #include "../cuda/cuda.hpp"
 #include "../intel/intel.hpp"
 
@@ -80,9 +81,19 @@ int get_num_gpus_available(struct gpu_list* list) {
   return list->num_gpus;
 }
 
+bool gpu_idx_valid(int idx) {
+  if(idx < 0) {
+    printErr("Specified GPU index is out of range: %d. ", idx);
+    printf("Run gpufetch with the --%s option to check out valid GPU indexes\n", args_str[ARG_LIST]);
+    return false;
+  }
+  return true;
+}
+
 struct gpu_info* get_gpu_info(struct gpu_list* list, int idx) {
   if(idx >= list->num_gpus || idx < 0) {
     printErr("Specified GPU index is out of range: %d", idx);
+    printf("Run gpufetch with the --%s option to check out valid GPU indexes\n", args_str[ARG_LIST]);
     return NULL;
   }
   return list->gpus[idx];
diff --git a/src/common/master.hpp b/src/common/master.hpp
index ad710c5..8de7b3a 100644
--- a/src/common/master.hpp
+++ b/src/common/master.hpp
@@ -9,6 +9,7 @@ struct gpu_list* get_gpu_list();
 bool print_gpus_list(struct gpu_list* list);
 int get_num_gpus_available(struct gpu_list* list);
 void print_enabled_backends();
+bool gpu_idx_valid(int idx);
 struct gpu_info* get_gpu_info(struct gpu_list* list, int idx);
 
 #endif
diff --git a/src/common/pci.cpp b/src/common/pci.cpp
index 692f9b5..3cc4d8b 100644
--- a/src/common/pci.cpp
+++ b/src/common/pci.cpp
@@ -99,18 +99,23 @@ void print_gpus_list_pci() {
   struct pci_dev *devices = get_pci_devices_from_pciutils();
 
   for(struct pci_dev *dev=devices; dev != NULL; dev=dev->next) {
-   if(dev->device_class == CLASS_VGA_CONTROLLER) {
-      printf("- GPU %d: ", i);
+    if(dev->device_class == CLASS_VGA_CONTROLLER) {
+      printf("- GPU %d:\n", i);
+      printf("  * Vendor: ");
       if(dev->vendor_id == PCI_VENDOR_ID_NVIDIA) {
-        printf("NVIDIA ");
+        printf("NVIDIA");
       }
       else if(dev->vendor_id == PCI_VENDOR_ID_INTEL) {
-        printf("Intel ");
+        printf("Intel");
       }
       else if(dev->vendor_id == PCI_VENDOR_ID_AMD) {
-        printf("AMD ");
+        printf("AMD");
       }
-      printf("%.4x:%.4x\n", dev->vendor_id, dev->device_id);
+      else {
+        printf("Unknown");
+      }
+      printf("\n  * PCI id: %.4x:%.4x\n", dev->vendor_id, dev->device_id);
+      i++;
     }
   }
 }