diff --git a/util/intelmetool/intelmetool.c b/util/intelmetool/intelmetool.c
index ae36fc58fc..5981e9ddbd 100644
--- a/util/intelmetool/intelmetool.c
+++ b/util/intelmetool/intelmetool.c
@@ -491,7 +491,8 @@ int main(int argc, char *argv[])
 	#ifndef __DARWIN__
 		fd_mem = open("/dev/mem", O_RDWR);
 		if (fd_mem < 0) {
-			perror("Can not open /dev/mem");
+			perror("Can not open /dev/mem. Do you have disabled "
+			       "Secure Boot ?");
 			exit(1);
 		}
 
diff --git a/util/intelmetool/rcba.c b/util/intelmetool/rcba.c
index c138e89fd3..ee43e65ce0 100644
--- a/util/intelmetool/rcba.c
+++ b/util/intelmetool/rcba.c
@@ -68,7 +68,8 @@ int write_rcba32(uint32_t addr, uint32_t val)
 
 	rcba = map_physical((off_t)rcba_phys, size);
 	if (rcba == NULL) {
-		printf("Could not map RCBA\n");
+		printf("Could not map RCBA\n"
+		       "Do you have cmdline argument 'iomem=relaxed' set ?\n");
 		return 1;
 	}
 	*(uint32_t *)(rcba + addr) = val;
@@ -93,7 +94,8 @@ int read_rcba32(uint32_t addr, uint32_t *val)
 
 	rcba = map_physical((off_t)rcba_phys, size);
 	if (rcba == NULL) {
-		printf("Could not map RCBA\n");
+		printf("Could not map RCBA\n"
+		       "Do you have cmdline argument 'iomem=relaxed' set ?\n");
 		return 1;
 	}