diff --git a/scripts/dts/gen_defines.py b/scripts/dts/gen_defines.py
index 86e61987c38..7cff885edfa 100755
--- a/scripts/dts/gen_defines.py
+++ b/scripts/dts/gen_defines.py
@@ -107,6 +107,16 @@ def main():
         for node in sorted(edt.nodes, key=lambda node: node.dep_ordinal):
             node.z_path_id = node_z_path_id(node)
 
+        # Check to see if we have duplicate "zephyr,memory-region" property values.
+        regions = dict()
+        for node in sorted(edt.nodes, key=lambda node: node.dep_ordinal):
+            if 'zephyr,memory-region' in node.props:
+                region = node.props['zephyr,memory-region'].val
+                if region in regions:
+                    sys.exit(f"ERROR: Duplicate 'zephyr,memory-region' ({region}) properties "
+                             f"between {regions[region].path} and {node.path}")
+                regions[region] = node
+
         for node in sorted(edt.nodes, key=lambda node: node.dep_ordinal):
             write_node_comment(node)