diff --git a/tradusquare_customization/checks/delta.py b/tradusquare_customization/checks/delta.py
new file mode 100644
index 0000000..009438c
--- /dev/null
+++ b/tradusquare_customization/checks/delta.py
@@ -0,0 +1,60 @@
+#   Copyright 2021 Tradusquare
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+"""Weblate checks for 'Deltarune' game."""
+
+import re
+
+from django.utils.translation import ugettext_lazy as _
+from weblate.checks.base import TargetCheck
+
+JSON_MATCH = re.compile(r"(?:\^[0-9])|(?:\/(?:%)+?$)|(?:\\[A-Za-z]{1,2}(?:[0-9]+)?)|(?:\[~[0-9]\])|(?:~[0-9])|(?:\/|%$)|(?:\\cY)|(?:\\cW)|(?:#)")
+
+
+class DeltaKeywordCheck(TargetCheck):
+    """
+    Custom checks for the Deltarune translation.
+
+    Adds a new check for the control codes like "\\E4"
+
+    It also adds highlighting.
+    """
+
+    check_id = "game-Delta"
+    name = _("Delta keywords")
+    description = _("Delta keywords are missing")
+    default_disabled = True
+
+    def check_highlight(self, source, unit):
+        """Highlight the control codes enclosed by the angles."""
+        if self.should_skip(unit):
+            return []
+        return [
+            (match.start(), match.end(), match.group())
+            for match in JSON_MATCH.finditer(source)
+        ]
+
+    # Real check code
+    def check_single(self, source, target, unit):
+        """Validate that the text contains the control code."""
+        src_match = JSON_MATCH.findall(source) 
+        tar_match = JSON_MATCH.findall(target)
+        if (len(src_match) != len(tar_match)):
+            return True
+        return False