--- a/physmap.c
+++ b/physmap.c
@@ -352,7 +352,7 @@ int setup_cpu_msr(int cpu)
 {
 	char msrfilename[64];
 	memset(msrfilename, 0, sizeof(msrfilename));
-	snprintf(msrfilename, sizeof(msrfilename), "/dev/cpu/%d/msr", cpu);
+	snprintf(msrfilename, sizeof(msrfilename), "/dev/msr%d", cpu);
 
 	if (fd_msr != -1) {
 		msg_pinfo("MSR was already initialized\n");
@@ -362,7 +362,8 @@ int setup_cpu_msr(int cpu)
 	fd_msr = open(msrfilename, O_RDWR);
 
 	if (fd_msr < 0) {
-		perror("Error while opening /dev/cpu/0/msr");
+		fprintf(stderr, "Error while opening %s: %s\n", msrfilename,
+			strerror(errno));
 		msg_pinfo("Did you run 'modprobe msr'?\n");
 		return -1;
 	}