diff --git a/mypy/test/data.py b/mypy/test/data.py
index a0573d55479c..cf4a4d6f14b8 100644
--- a/mypy/test/data.py
+++ b/mypy/test/data.py
@@ -383,7 +383,7 @@ def expand_errors(input: List[str], output: List[str], fnam: str) -> None:
 
     for i in range(len(input)):
         # The first in the split things isn't a comment
-        for possible_err_comment in input[i].split('#')[1:]:
+        for possible_err_comment in input[i].split(' # ')[1:]:
             m = re.search(
                 '^([ENW]):((?P<col>\d+):)? (?P<message>.*)$',
                 possible_err_comment.strip())
diff --git a/test-data/unit/check-abstract.test b/test-data/unit/check-abstract.test
index 2de9d129436b..9a0d4afc5971 100644
--- a/test-data/unit/check-abstract.test
+++ b/test-data/unit/check-abstract.test
@@ -154,7 +154,7 @@ class A(metaclass=ABCMeta):
   @abstractmethod
   def g(self): pass
 class B(A): pass
-B()# E: Cannot instantiate abstract class 'B' with abstract attributes 'f' and 'g'
+B() # E: Cannot instantiate abstract class 'B' with abstract attributes 'f' and 'g'
 [out]
 
 [case testInstantiationAbstractsInTypeForFunctions]