diff --git a/src/core/nm-core-utils.c b/src/core/nm-core-utils.c
index 085c806c12..25d1ec807f 100644
--- a/src/core/nm-core-utils.c
+++ b/src/core/nm-core-utils.c
@@ -5222,7 +5222,7 @@ again:
  * @shortened: (out) (transfer full): on return, the shortened hostname
  *
  * Checks whether the input hostname is valid. If not, tries to shorten it
- * to HOST_NAME_MAX or to the first dot, whatever comes earlier.
+ * to HOST_NAME_MAX (64) or to the first dot, whatever comes earlier.
  * The new hostname is returned in @shortened.
  *
  * Returns: %TRUE if the input hostname was already valid or if was shortened
@@ -5248,7 +5248,7 @@ nm_utils_shorten_hostname(const char *hostname, char **shortened)
         l = (dot - hostname);
     else
         l = strlen(hostname);
-    l = MIN(l, (gsize) HOST_NAME_MAX);
+    l = MIN(l, (gsize) NM_HOST_NAME_MAX);
 
     s = g_strndup(hostname, l);
 
diff --git a/src/core/tests/test-utils.c b/src/core/tests/test-utils.c
index ad9950ddb4..2bcb6f6946 100644
--- a/src/core/tests/test-utils.c
+++ b/src/core/tests/test-utils.c
@@ -234,8 +234,10 @@ test_shorten_hostname(void)
      * system configuration (`getconf HOST_NAME_MAX`). On Linux
      * it's typically 64 characters, but POSIX allows up to
      * 255 characters.
+     *
+     * We use our own define NM_HOST_NAME_MAX, which is always 64.
      */
-    maxhost = g_strnfill(HOST_NAME_MAX, 'a');
+    maxhost = g_strnfill(NM_HOST_NAME_MAX, 'a');
 
     do_test_shorten_hostname("name1", TRUE, NULL);
 
diff --git a/src/libnm-glib-aux/nm-shared-utils.c b/src/libnm-glib-aux/nm-shared-utils.c
index 0756bad45b..f305a7aa13 100644
--- a/src/libnm-glib-aux/nm-shared-utils.c
+++ b/src/libnm-glib-aux/nm-shared-utils.c
@@ -6585,7 +6585,7 @@ nm_utils_validate_hostname(const char *hostname)
     if (dot)
         return FALSE;
 
-    return (p - hostname <= HOST_NAME_MAX);
+    return (p - hostname <= NM_HOST_NAME_MAX);
 }
 
 /*****************************************************************************/
@@ -7246,7 +7246,7 @@ nm_hostname_is_valid(const char *s, gboolean trailing_dot)
 
     /* Note that HOST_NAME_MAX is 64 on Linux, but DNS allows domain names up to
      * 255 characters */
-    if (p - s > HOST_NAME_MAX)
+    if (p - s > NM_HOST_NAME_MAX)
         return FALSE;
 
     return TRUE;
diff --git a/src/libnm-glib-aux/nm-shared-utils.h b/src/libnm-glib-aux/nm-shared-utils.h
index 14b6302662..ec57190e50 100644
--- a/src/libnm-glib-aux/nm-shared-utils.h
+++ b/src/libnm-glib-aux/nm-shared-utils.h
@@ -3256,6 +3256,12 @@ char *_nm_utils_format_variant_attributes(GHashTable                          *a
 
 /*****************************************************************************/
 
+/* glibc defines HOST_NAME_MAX as 64. Also Linux' sethostname() enforces
+ * that (__NEW_UTS_LEN). However, musl sets this to 255.
+ *
+ * At some places, we want to follow Linux. Hardcode our own define. */
+#define NM_HOST_NAME_MAX 64
+
 gboolean nm_utils_is_localhost(const char *name);
 
 gboolean nm_utils_is_specific_hostname(const char *name);
diff --git a/src/libnm-glib-aux/tests/test-shared-general.c b/src/libnm-glib-aux/tests/test-shared-general.c
index 15e709b62c..ccd1b1c37b 100644
--- a/src/libnm-glib-aux/tests/test-shared-general.c
+++ b/src/libnm-glib-aux/tests/test-shared-general.c
@@ -2120,6 +2120,8 @@ test_hostname_is_valid(void)
     g_assert(!nm_hostname_is_valid("foo..bar", FALSE));
     g_assert(!nm_hostname_is_valid("foo.bar..", FALSE));
 
+    G_STATIC_ASSERT_EXPR(NM_HOST_NAME_MAX <= HOST_NAME_MAX);
+
 #define _assert_hostname_length(n, valid)         \
     G_STMT_START                                  \
     {                                             \
@@ -2132,16 +2134,15 @@ test_hostname_is_valid(void)
     }                                             \
     G_STMT_END
 
-    _assert_hostname_length(HOST_NAME_MAX - 10, TRUE);
-    _assert_hostname_length(HOST_NAME_MAX - 1, TRUE);
-    _assert_hostname_length(HOST_NAME_MAX, TRUE);
-    _assert_hostname_length(HOST_NAME_MAX + 1, FALSE);
-    _assert_hostname_length(HOST_NAME_MAX + 10, FALSE);
+    _assert_hostname_length(NM_HOST_NAME_MAX - 10, TRUE);
+    _assert_hostname_length(NM_HOST_NAME_MAX - 1, TRUE);
+    _assert_hostname_length(NM_HOST_NAME_MAX, TRUE);
+    _assert_hostname_length(NM_HOST_NAME_MAX + 1, FALSE);
+    _assert_hostname_length(NM_HOST_NAME_MAX + 10, FALSE);
 
-    g_assert(nm_hostname_is_valid(
-                 "au-xph5-rvgrdsb5hcxc-47et3a5vvkrc-server-wyoz4elpdpe3.openstack.local",
-                 FALSE)
-             == (HOST_NAME_MAX >= 69));
+    g_assert(!nm_hostname_is_valid(
+        "au-xph5-rvgrdsb5hcxc-47et3a5vvkrc-server-wyoz4elpdpe3.openstack.local",
+        FALSE));
 
     g_assert(nm_hostname_is_valid("foobar", TRUE));
     g_assert(nm_hostname_is_valid("foobar.com", TRUE));
@@ -2160,13 +2161,11 @@ test_hostname_is_valid(void)
     g_assert(!nm_hostname_is_valid("foo.bar..", TRUE));
     g_assert(
         nm_hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
-                             TRUE)
-        == (HOST_NAME_MAX >= 64));
+                             TRUE));
     g_assert(
-        nm_hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-                             "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
-                             TRUE)
-        == (HOST_NAME_MAX >= 104));
+        !nm_hostname_is_valid("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+                              "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
+                              TRUE));
 }
 
 /*****************************************************************************/