diff --git a/libnm-core/nm-utils.c b/libnm-core/nm-utils.c
index 6384e2e9a1..ab5de92a46 100644
--- a/libnm-core/nm-utils.c
+++ b/libnm-core/nm-utils.c
@@ -3995,16 +3995,13 @@ GByteArray *
 nm_utils_hwaddr_atoba(const char *asc, gsize length)
 {
     GByteArray *ba;
-    gsize       l;
 
     g_return_val_if_fail(asc, NULL);
     g_return_val_if_fail(length > 0 && length <= NM_UTILS_HWADDR_LEN_MAX, NULL);
 
     ba = g_byte_array_sized_new(length);
     g_byte_array_set_size(ba, length);
-    if (!_nm_utils_hwaddr_aton(asc, ba->data, length, &l))
-        goto fail;
-    if (length != l)
+    if (!_nm_utils_hwaddr_aton_exact(asc, ba->data, length))
         goto fail;
 
     return ba;
@@ -4029,17 +4026,11 @@ fail:
 guint8 *
 nm_utils_hwaddr_aton(const char *asc, gpointer buffer, gsize length)
 {
-    gsize l;
-
     g_return_val_if_fail(asc, NULL);
     g_return_val_if_fail(buffer, NULL);
     g_return_val_if_fail(length > 0 && length <= NM_UTILS_HWADDR_LEN_MAX, NULL);
 
-    if (!_nm_utils_hwaddr_aton(asc, buffer, length, &l))
-        return NULL;
-    if (length != l)
-        return NULL;
-    return buffer;
+    return _nm_utils_hwaddr_aton_exact(asc, buffer, length);
 }
 
 /**
diff --git a/shared/nm-glib-aux/nm-shared-utils.h b/shared/nm-glib-aux/nm-shared-utils.h
index fe61459f5f..abcb20abaf 100644
--- a/shared/nm-glib-aux/nm-shared-utils.h
+++ b/shared/nm-glib-aux/nm-shared-utils.h
@@ -2092,6 +2092,24 @@ _nm_utils_hwaddr_aton(const char *asc, gpointer buffer, gsize buffer_length, gsi
                                     out_length);
 }
 
+static inline guint8 *
+_nm_utils_hwaddr_aton_exact(const char *asc, gpointer buffer, gsize buffer_length)
+{
+    g_return_val_if_fail(asc, NULL);
+    g_return_val_if_fail(buffer, NULL);
+    g_return_val_if_fail(buffer_length > 0, NULL);
+
+    return nm_utils_hexstr2bin_full(asc,
+                                    FALSE,
+                                    TRUE,
+                                    FALSE,
+                                    ":-",
+                                    buffer_length,
+                                    buffer,
+                                    buffer_length,
+                                    NULL);
+}
+
 static inline const char *
 _nm_utils_hwaddr_ntoa(gconstpointer addr,
                       gsize         addr_len,
diff --git a/src/platform/nm-platform-utils.c b/src/platform/nm-platform-utils.c
index f0dfc074a7..75ac769a74 100644
--- a/src/platform/nm-platform-utils.c
+++ b/src/platform/nm-platform-utils.c
@@ -1439,7 +1439,7 @@ nmp_utils_ethtool_set_wake_on_lan(int                     ifindex,
         wol_info.wolopts |= WAKE_MAGIC;
 
     if (wol_password) {
-        if (!nm_utils_hwaddr_aton(wol_password, wol_info.sopass, ETH_ALEN)) {
+        if (!_nm_utils_hwaddr_aton_exact(wol_password, wol_info.sopass, ETH_ALEN)) {
             nm_log_dbg(LOGD_PLATFORM,
                        "ethtool[%d]: couldn't parse Wake-on-LAN password '%s'",
                        ifindex,