diff --git a/corrlib/integrity.py b/corrlib/integrity.py
index db242f6..8a414bf 100644
--- a/corrlib/integrity.py
+++ b/corrlib/integrity.py
@@ -15,9 +15,21 @@ def has_valid_times(result: pd.DataFrame) -> bool:
         return False
     return True
 
+def are_keys_unique(db: Path, table: str, col: str) -> bool:
+    conn = sqlite3.connect(db)
+    c = conn.cursor()
+    c.execute(f"SELECT COUNT( DISTINCT CAST(path AS nvarchar(4000))), COUNT({col}) FROM {table};")
+    results = c.fetchall()[0]
+    conn.close()
+    return bool(results[0] == results[1])
+
 
 def check_db_integrity(path: Path) -> None:
     db = get_db_file(path)
+
+    if not are_keys_unique(db, 'backlogs', 'path'):
+        raise Exception("The paths the backlog table of the database links are not unique.")
+
     search_expr = "SELECT * FROM 'backlogs'"
     conn = sqlite3.connect(db)
     results = pd.read_sql(search_expr, conn)
@@ -27,6 +39,7 @@ def check_db_integrity(path: Path) -> None:
             raise ValueError(f"Result with id {result[id]} has wrong time signatures.")
 
 
+
 def full_integrity_check(path: Path) -> None:
     check_db_integrity(path)