diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index c6b0796de478..382d139617de 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -866,7 +866,7 @@ acpi_child_location_str_method(device_t cbdev, device_t child, char *buf,
                 strlcat(buf, buf2, buflen);
         }
     } else {
-        snprintf(buf, buflen, "unknown");
+        snprintf(buf, buflen, "");
     }
     return (0);
 }
diff --git a/sys/dev/nvdimm/nvdimm.c b/sys/dev/nvdimm/nvdimm.c
index 5c6b6ee6dc72..e7d13cbf20f7 100644
--- a/sys/dev/nvdimm/nvdimm.c
+++ b/sys/dev/nvdimm/nvdimm.c
@@ -571,7 +571,7 @@ nvdimm_root_child_location_str(device_t dev, device_t child, char *buf,
 	if (handle != NULL)
 		res = snprintf(buf, buflen, "handle=%s", acpi_name(handle));
 	else
-		res = snprintf(buf, buflen, "unknown");
+		res = snprintf(buf, buflen, "");
 
 	if (res >= buflen)
 		return (EOVERFLOW);