diff --git a/scripts/set b/scripts/set
index bb16d5e2..297c04ea 100755
--- a/scripts/set
+++ b/scripts/set
@@ -57,9 +57,6 @@ else
   esac
 fi
 
-perl_line="\$yaml->{${option//./\}->\{}}=${value};"
-log_debug "perl line: ${perl_line}"
-
 tmp=$(mktemp)
 log_debug "Temporary perl file: ${tmp}"
 
@@ -69,8 +66,34 @@ use warnings;
 use YAML::XS;
 my \$file="${file}";
 my \$yaml = YAML::XS::LoadFile("\$file");
-
-${perl_line}
+my \$valref = \\\$yaml;
+
+for my \$component (split(/\\./, "${option}")) {
+  if (ref(\$valref) eq 'SCALAR' && defined(\$\$valref)) {
+    print STDERR ("Key resolved to a SCALAR at '\$component'; cannot continue.\n");
+    exit(1);
+  }
+  elsif (\$component =~ /^\\d+\$/ && (!defined(\$\$valref) || ref(\$\$valref) eq 'ARRAY')) {
+    \$valref = \\\$\$valref->[\$component];
+  }
+  elsif (\$component eq 'APPEND' && ref(\$\$valref) eq 'ARRAY') {
+    \$valref = \\\$\$valref->[\$#{\$\$valref}+1];
+  }
+  elsif (!defined(\$\$valref) || ref(\$\$valref) eq 'HASH') {
+    \$valref = \\\$\$valref->{\$component};
+  }
+  else {
+    print STDERR ("Key resolved to a " . ref(\$\$valref) . " reference; refusing to overwrite.\n");
+    exit(1);
+  }
+}
+if (!defined(\$\$valref) || ref(\$valref) eq 'SCALAR') {
+  \$\$valref = ${value};
+}
+else {
+  print STDERR ("Key resolved to a " . ref(\$\$valref) . " reference; refusing to overwrite.\n");
+  exit(1);
+}
 
 YAML::XS::DumpFile(\$file, \$yaml);
 EOF
diff --git a/t/test_ngcpcfg_set_and_del.py b/t/test_ngcpcfg_set_and_del.py
index a4bb1eee..29a70be1 100644
--- a/t/test_ngcpcfg_set_and_del.py
+++ b/t/test_ngcpcfg_set_and_del.py
@@ -235,6 +235,200 @@ foo:
     assert out.returncode == 0
 
 
+@pytest.mark.tt_33030
+def test_set_action_set_array_element(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - 'blah'
+  - 'baz'
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar.0=\'moo\'")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - moo
+  - baz
+'''
+    assert "" in out.stdout
+    assert "" in out.stderr
+    assert out.returncode == 0
+
+
+@pytest.mark.tt_33030
+def test_set_action_append_array_element(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - blah
+  - baz
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar.2=\'moo\'")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - blah
+  - baz
+  - moo
+'''
+    assert "" in out.stdout
+    assert "" in out.stderr
+    assert out.returncode == 0
+
+
+@pytest.mark.tt_33030
+def test_set_action_auto_append_array_element(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - blah
+  - baz
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar.APPEND=\'moo\'")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - blah
+  - baz
+  - moo
+'''
+    assert "" in out.stdout
+    assert "" in out.stderr
+    assert out.returncode == 0
+
+
+@pytest.mark.tt_33030
+def test_set_action_add_new_array_one_element(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  moo: blah
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar.0=\'boo\'")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - boo
+  moo: blah
+'''
+    assert "" in out.stdout
+    assert "" in out.stderr
+    assert out.returncode == 0
+
+
+@pytest.mark.tt_33030
+def test_set_action_set_array_subelement(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar.1.foo=\'boo\'")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: boo
+  moo: blah
+'''
+    assert "" in out.stdout
+    assert "" in out.stderr
+    assert out.returncode == 0
+
+
+@pytest.mark.tt_33030
+def test_set_action_set_hash_instead_of_array(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar.baz=123")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+'''
+    assert "" in out.stdout
+    assert "Key resolved to a ARRAY reference; refusing to overwrite." \
+        in out.stderr
+    assert out.returncode == 1
+
+
+@pytest.mark.tt_33030
+def test_set_action_set_array_instead_of_scalar(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo.bar=123")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+'''
+    assert "" in out.stdout
+    assert "Key resolved to a ARRAY reference; refusing to overwrite." \
+        in out.stderr
+    assert out.returncode == 1
+
+
+@pytest.mark.tt_33030
+def test_set_action_set_hash_instead_of_scalar(ngcpcfgcli, tmpdir):
+    tmpfile = tmpdir.join("tmpfile.txt")
+    tmpfile.write('''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+''')
+    out = ngcpcfgcli("set", str(tmpfile), "foo=123")
+    assert tmpfile.read() == '''---
+foo:
+  bar:
+  - blah: quux
+    foo: meh
+  - blah: zarg
+    foo: ruuk
+  moo: blah
+'''
+    assert "" in out.stdout
+    assert "Key resolved to a HASH reference; refusing to overwrite." \
+        in out.stderr
+    assert out.returncode == 1
+
 ###############################################################
 #  ngcpcfg del
 ###############################################################