diff --git a/src/basic/proc-cmdline.c b/src/basic/proc-cmdline.c
index 39e9f2c668..6203b79959 100644
--- a/src/basic/proc-cmdline.c
+++ b/src/basic/proc-cmdline.c
@@ -98,7 +98,7 @@ int proc_cmdline(char **ret) {
         if (detect_container() > 0)
                 return get_process_cmdline(1, SIZE_MAX, 0, ret);
         else
-                return read_one_line_file("/proc/cmdline", ret);
+                return read_full_file("/proc/cmdline", ret, NULL);
 }
 
 static int proc_cmdline_strv_internal(char ***ret, bool filter_pid1_args) {
@@ -128,7 +128,7 @@ static int proc_cmdline_strv_internal(char ***ret, bool filter_pid1_args) {
         } else {
                 _cleanup_free_ char *s = NULL;
 
-                r = read_one_line_file("/proc/cmdline", &s);
+                r = read_full_file("/proc/cmdline", &s, NULL);
                 if (r < 0)
                         return r;
 
diff --git a/test/TEST-02-UNITTESTS/test.sh b/test/TEST-02-UNITTESTS/test.sh
index 3d766db3e7..3646aa678e 100755
--- a/test/TEST-02-UNITTESTS/test.sh
+++ b/test/TEST-02-UNITTESTS/test.sh
@@ -14,6 +14,9 @@ KERNEL_APPEND="
 
 frobnicate!
 
+systemd.setenv=TEST_CMDLINE_NEWLINE=foo
+systemd.setenv=TEST_CMDLINE_NEWLINE=bar
+
 $KERNEL_APPEND
 "
 
diff --git a/test/units/testsuite-02.sh b/test/units/testsuite-02.sh
index d8aaacb913..ca54fc4018 100755
--- a/test/units/testsuite-02.sh
+++ b/test/units/testsuite-02.sh
@@ -3,6 +3,12 @@
 set -eux
 set -o pipefail
 
+if ! systemd-detect-virt -qc && [[ "${TEST_CMDLINE_NEWLINE:-}" != bar ]]; then
+    cat /proc/cmdline
+    echo >&2 "Expected TEST_CMDLINE_NEWLINE=bar from the kernel command line"
+    exit 1
+fi
+
 NPROC=$(nproc)
 MAX_QUEUE_SIZE=${NPROC:-2}
 TESTS_GLOB=${TESTS_GLOB:-test-*}