diff --git a/ddtrace/_trace/tracer.py b/ddtrace/_trace/tracer.py
index ee28f529091..055da2c3cf5 100644
--- a/ddtrace/_trace/tracer.py
+++ b/ddtrace/_trace/tracer.py
@@ -217,7 +217,7 @@ def __init__(
                 Tracer._instance = self
             else:
                 ValueError(
-                    "Multiple Tracer instances can not be iniitalized. Use ddtrace.trace.tracer instead.",
+                    "Multiple Tracer instances can not be initialized. Use ``ddtrace.trace.tracer`` instead.",
                 )
 
         self._user_trace_processors: List[TraceProcessor] = []
diff --git a/tests/utils.py b/tests/utils.py
index b003476ab82..6fa7d2b8044 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -650,9 +650,9 @@ def configure(self, *args, **kwargs):
         self._configure(*args, **kwargs)
 
     def _configure(self, *args, **kwargs):
-        assert "writer" in kwargs and not isinstance(
+        assert not("writer" in kwargs and not isinstance(
             kwargs["writer"], DummyWriterMixin
-        ), "cannot configure writer of DummyTracer"
+        )), "cannot configure writer of DummyTracer"
 
         if not kwargs.get("writer"):
             # if no writer is present, check if test agent is running to determine if we