diff --git a/src/basic/fd-util.c b/src/basic/fd-util.c
index a3dced441a..e2bee51147 100644
--- a/src/basic/fd-util.c
+++ b/src/basic/fd-util.c
@@ -21,9 +21,10 @@
 #include "path-util.h"
 #include "process-util.h"
 #include "socket-util.h"
+#include "stat-util.h"
 #include "stdio-util.h"
-#include "util.h"
 #include "tmpfile-util.h"
+#include "util.h"
 
 /* The maximum number of iterations in the loop to close descriptors in the fallback case
  * when /proc/self/fd/ is inaccessible. */
@@ -939,8 +940,15 @@ int fd_reopen(int fd, int flags) {
 
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);
         new_fd = open(procfs_path, flags);
-        if (new_fd < 0)
-                return -errno;
+        if (new_fd < 0) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                if (proc_mounted() == 0)
+                        return -ENOSYS; /* if we have no /proc/, the concept is not implementable */
+
+                return -ENOENT;
+        }
 
         return new_fd;
 }
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index ef3b5a5184..e16bfef3c3 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -337,8 +337,15 @@ int fchmod_opath(int fd, mode_t m) {
          * fchownat() does. */
 
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);
-        if (chmod(procfs_path, m) < 0)
-                return -errno;
+        if (chmod(procfs_path, m) < 0) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                if (proc_mounted() == 0)
+                        return -ENOSYS; /* if we have no /proc/, the concept is not implementable */
+
+                return -ENOENT;
+        }
 
         return 0;
 }
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index 6f0dc2426e..ff1dff13da 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -1078,6 +1078,11 @@ static int fd_set_acls(Item *item, int fd, const char *path, const struct stat *
 
         if (r > 0)
                 return -r; /* already warned */
+
+        /* The above procfs paths don't work if /proc is not mounted. */
+        if (r == -ENOENT && proc_mounted() == 0)
+                r = -ENOSYS;
+
         if (r == -EOPNOTSUPP) {
                 log_debug_errno(r, "ACLs not supported by file system at %s", path);
                 return 0;