diff --git a/Makefile b/Makefile
index f7e1633..65558dd 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 all:
-	gcc -std=c99 -O3 -Wall -Wextra -o gddr6 gddr6.c -lpci 
+	gcc -std=c11 -O3 -Wall -Werror -Wextra  -Wshadow -Wpointer-arith -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -Wvla -o gddr6 gddr6.c -lpci
 clean:
 	rm -f gddr6
 
diff --git a/gddr6.c b/gddr6.c
index 17c0099..5bc4ab0 100644
--- a/gddr6.c
+++ b/gddr6.c
@@ -14,6 +14,9 @@
                 __LINE__, __FILE__, errno, strerror(errno)); exit(1);    \
                 } while(0)
 
+// prototypes
+struct device * pci_detect_dev(void);
+
 struct device 
 {
     uint32_t bar0;
@@ -32,10 +35,10 @@ static struct device dev_table[] =
     { .bar0 = 0xFB000000, .offset = 0x0000EE50, .dev_id = 0x2488, .vram = "GDDR6",  .arch = "GA104", .name =  "RTX 3070-LHR" },
 };
 
-struct device * pci_detect_dev() 
+struct device * pci_detect_dev(void) 
 {
     struct pci_access *pacc = NULL;
-    struct pci_dev *dev = NULL;
+    struct pci_dev *pci_dev = NULL;
     struct device *device = NULL;
     ssize_t dev_table_size = (sizeof(dev_table)/sizeof(struct device));
 
@@ -43,26 +46,26 @@ struct device * pci_detect_dev()
     pci_init(pacc);
     pci_scan_bus(pacc);
 
-    for (dev = pacc->devices; dev; dev = dev->next) 
+    for (pci_dev = pacc->devices; pci_dev; pci_dev = pci_dev->next) 
     {
-        pci_fill_info(dev, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_CLASS);
+        pci_fill_info(pci_dev, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_CLASS);
 
         for (uint32_t i = 0; i < dev_table_size; i++) 
         {
-            if (dev->device_id == dev_table[i].dev_id) 
+            if (pci_dev->device_id == dev_table[i].dev_id) 
             {
                 device = &dev_table[i]; 
 
-                if (dev->base_addr[0] != device->bar0) 
+                if (pci_dev->base_addr[0] != device->bar0) 
                 {
-                    device->bar0 = dev->base_addr[0];
+                    device->bar0 = pci_dev->base_addr[0];
                 }
 
                 break;
             }
         }
     }
-
+    
     pci_cleanup(pacc);
     return device;
 }
@@ -71,24 +74,23 @@ int main(int argc, char **argv)
 {
     (void) argc;
     (void) argv;
-
     int fd;
     void *map_base;
     void *virt_addr;
-    uint32_t temp;
+    double temp;
     uint32_t phys_addr;
     uint32_t read_result;
     uint32_t base_offset;
-    uint32_t map_size = 0x1000;
+    uint32_t map_size;
+
     struct device *device = NULL; 
     char *MEM = "\x2f\x64\x65\x76\x2f\x6d\x65\x6d";
 
     device = pci_detect_dev();
-    phys_addr = device->bar0 + device->offset;
 
     if (device == NULL) 
     {
-        printf("No compatible devices device. \n");
+        printf("No compatible GPU found\n.");
         exit(-1);
     }
 
@@ -100,6 +102,8 @@ int main(int argc, char **argv)
         PRINT_ERROR();
     }
 
+    map_size = 0x1000;
+    phys_addr = (device->bar0 + device->offset);
     base_offset = phys_addr & ~(sysconf(_SC_PAGE_SIZE)-1);
     map_base = mmap(0, map_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, base_offset);
 
@@ -111,12 +115,12 @@ int main(int argc, char **argv)
 
     while (1)
     {
-        virt_addr = (map_base + (phys_addr - base_offset));
+        virt_addr = (uint8_t *) map_base + (phys_addr - base_offset);
         read_result = *((uint32_t *) virt_addr);
 
         temp = ((read_result & 0x00000fff) / 0x20);
 
-        printf("\r%s VRAM Temp: %d°c", device->vram, temp);
+        printf("\r%s VRAM Temp: %.1f°c", device->vram, temp);
         fflush(stdout);
 
         sleep(1);