diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 2da02b2662e5596ab47c4a6eaed26fdbeceeb466..03a873c904be78214bfa030f862596b05fdf1b91 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -479,7 +479,10 @@ if platform.system() == 'Windows':
   def make_jobspec(cfg, targets):
     extra_args = []
     if args.travis:
-      extra_args.extend(["/m", "/p:GenerateDebugInformation=false"])
+      # better do parallel compilation
+      extra_args.extend(["/m"])
+      # disable PDB generation: it's broken, and we don't need it during CI
+      extra_args.extend(["/p:GenerateDebugInformation=false", "/p:DebugInformationFormat=None"])
     return [
       jobset.JobSpec(['vsprojects\\build.bat', 
                       'vsprojects\\%s.sln' % target,