diff --git a/gitlab-bot/ghc_perf_import_service/__init__.py b/gitlab-bot/ghc_perf_import_service/__init__.py
index 4f5f015dfc41e9822ba8990b764310527bd795ec..c5e47da046a5c6338a59fe03a6c9511a48fba90d 100644
--- a/gitlab-bot/ghc_perf_import_service/__init__.py
+++ b/gitlab-bot/ghc_perf_import_service/__init__.py
@@ -214,8 +214,8 @@ class GHCPerfWebhookServer(WebhookServer):
                 # This may cause false negatives, but I think that's the lesser
                 # of two evils.
                 and not (
-                    trace.find(b'GHC.IO.FD.fdWrite: resource exhausted')
-                    or trace.find(b'<stdout>: hFlush: resource exhausted')
+                    trace.find(b'GHC.IO.FD.fdWrite: resource exhausted') >= 0
+                    or trace.find(b'<stdout>: hFlush: resource exhausted') >= 0
                 )):
             joblog('exhausted disk')
             failures.append('no_space')
@@ -276,11 +276,11 @@ class GHCPerfWebhookServer(WebhookServer):
             joblog('ulimit: Invalid argument')
             failures.append('ulimit')
         # #23039
-        if trace.find(b'fresh repository.\x1b[0;m\nerror'):
+        if trace.find(b'fresh repository.\x1b[0;m\nerror') >= 0:
             joblog('error cloning fresh repository')
             failures.append('repo_clone')
         # #23039 again
-        if trace.find(b'refs/notes/perf:refs/notes/perf\nerror:'):
+        if trace.find(b'refs/notes/perf:refs/notes/perf\nerror:') >= 0:
             joblog('error fetch perf notes')
             failures.append('perf_note_fetch')
         ## ... others to be added...