diff --git a/pyright_to_rdjson/pyright_to_rdjson.py b/pyright_to_rdjson/pyright_to_rdjson.py
index a0c8cb3..ac0ebe4 100755
--- a/pyright_to_rdjson/pyright_to_rdjson.py
+++ b/pyright_to_rdjson/pyright_to_rdjson.py
@@ -33,12 +33,13 @@ def pyright_to_rdjson(jsonin: TextIO):
                     "path": d["file"],
                     "range": {
                         "start": {
-                            "line": d["range"]["start"]["line"],
-                            "column": d["range"]["start"]["character"],
+                            # pyright uses zero-based offsets
+                            "line": d["range"]["start"]["line"] + 1,
+                            "column": d["range"]["start"]["character"] + 1,
                         },
                         "end": {
-                            "line": d["range"]["end"]["line"],
-                            "column": d["range"]["end"]["character"],
+                            "line": d["range"]["end"]["line"] + 1,
+                            "column": d["range"]["end"]["character"] + 1,
                         },
                     },
                 },
diff --git a/pyright_to_rdjson/tests/test_pyright_to_rdjson.py b/pyright_to_rdjson/tests/test_pyright_to_rdjson.py
index 02b32e2..18cb9b4 100755
--- a/pyright_to_rdjson/tests/test_pyright_to_rdjson.py
+++ b/pyright_to_rdjson/tests/test_pyright_to_rdjson.py
@@ -43,8 +43,9 @@ def test_pyright_to_rdjson(self):
             pyright_line_start = pyright_line_range["start"]
             pyright_line_end = pyright_line_range["end"]
 
-            assert rdjson_line_start["line"] == pyright_line_start["line"]
-            assert rdjson_line_start["column"] == pyright_line_start["character"]
+            # pyrights offsets are zero-based
+            assert rdjson_line_start["line"] == pyright_line_start["line"] + 1
+            assert rdjson_line_start["column"] == pyright_line_start["character"] + 1
 
-            assert rdjson_line_end["line"] == pyright_line_end["line"]
-            assert rdjson_line_end["column"] == pyright_line_end["character"]
+            assert rdjson_line_end["line"] == pyright_line_end["line"] + 1
+            assert rdjson_line_end["column"] == pyright_line_end["character"] + 1