diff --git a/Lib/bdb.py b/Lib/bdb.py
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@@ -230,10 +230,6 @@
         if not self.breaks:
             # no breakpoints; run without debugger overhead
             sys.settrace(None)
-            frame = sys._getframe().f_back
-            while frame and frame is not self.botframe:
-                del frame.f_trace
-                frame = frame.f_back
 
     def set_quit(self):
         self.stopframe = self.botframe
diff --git a/Lib/test/test_sys_settrace.py b/Lib/test/test_sys_settrace.py
--- a/Lib/test/test_sys_settrace.py
+++ b/Lib/test/test_sys_settrace.py
@@ -5,6 +5,7 @@
 import sys
 import difflib
 import gc
+import textwrap
 
 # A very basic example.  If this fails, we're in deep trouble.
 def basic():
@@ -388,6 +389,34 @@
              (257, 'line'),
              (257, 'return')])
 
+    def test_17_backtrace_lineno(self):
+        # issue17277: line numbers in backtrace after removing the trace
+        # function.
+        tracer = Tracer()
+        sys.settrace(tracer.trace)
+        source = """
+            def bar():
+                sys.settrace(None)
+
+            def foo():
+                bar()
+                line_number = 7
+                1 / 0
+
+            foo()
+        """
+
+        lno = 0
+        try:
+            exec(textwrap.dedent(source), globals())
+        except ZeroDivisionError:
+            tb = sys.exc_info()[2]
+            while tb:
+                lno = tb.tb_lineno
+                tb = tb.tb_next
+        self.assertEqual(lno, 8, 'Bad line number in traceback after'
+                                        ' removing the trace function.')
+
 
 class RaisingTraceFuncTestCase(unittest.TestCase):
     def setUp(self):
diff --git a/Python/traceback.c b/Python/traceback.c
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -118,7 +118,8 @@
         Py_XINCREF(frame);
         tb->tb_frame = frame;
         tb->tb_lasti = frame->f_lasti;
-        tb->tb_lineno = PyFrame_GetLineNumber(frame);
+        tb->tb_lineno = PyCode_Addr2Line(frame->f_code,
+                                        frame->f_lasti);
         PyObject_GC_Track(tb);
     }
     return tb;