diff --git a/moto/secretsmanager/models.py b/moto/secretsmanager/models.py
index f7cb855eb..b46e04d6c 100644
--- a/moto/secretsmanager/models.py
+++ b/moto/secretsmanager/models.py
@@ -46,7 +46,7 @@ class SecretsManagerBackend(BaseBackend):
     def get_secret_value(self, secret_id, version_id, version_stage):
 
         if not self._is_valid_identifier(secret_id):
-            raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+            raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         if not version_id and version_stage:
             # set version_id to match version_stage
@@ -56,7 +56,7 @@ class SecretsManagerBackend(BaseBackend):
                     version_id = ver_id
                     break
             if not version_id:
-                raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+                raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         # TODO check this part
         if 'deleted_date' in self.secrets[secret_id]:
@@ -175,7 +175,7 @@ class SecretsManagerBackend(BaseBackend):
 
     def describe_secret(self, secret_id):
         if not self._is_valid_identifier(secret_id):
-            raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+            raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         secret = self.secrets[secret_id]
 
@@ -204,7 +204,7 @@ class SecretsManagerBackend(BaseBackend):
         rotation_days = 'AutomaticallyAfterDays'
 
         if not self._is_valid_identifier(secret_id):
-            raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+            raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         if 'deleted_date' in self.secrets[secret_id]:
             raise InvalidRequestException(
@@ -346,7 +346,7 @@ class SecretsManagerBackend(BaseBackend):
     def delete_secret(self, secret_id, recovery_window_in_days, force_delete_without_recovery):
 
         if not self._is_valid_identifier(secret_id):
-            raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+            raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         if 'deleted_date' in self.secrets[secret_id]:
             raise InvalidRequestException(
@@ -376,7 +376,7 @@ class SecretsManagerBackend(BaseBackend):
             secret = self.secrets.get(secret_id, None)
 
         if not secret:
-            raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+            raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         arn = secret_arn(self.region, secret['secret_id'])
         name = secret['name']
@@ -386,7 +386,7 @@ class SecretsManagerBackend(BaseBackend):
     def restore_secret(self, secret_id):
 
         if not self._is_valid_identifier(secret_id):
-            raise ResourceNotFoundException("Secrets Manager can't find the specified secret")
+            raise ResourceNotFoundException("Secrets Manager can’t find the specified secret.")
 
         self.secrets[secret_id].pop('deleted_date', None)
 
diff --git a/tests/test_secretsmanager/test_secretsmanager.py b/tests/test_secretsmanager/test_secretsmanager.py
index b77fa70d0..7273b5c21 100644
--- a/tests/test_secretsmanager/test_secretsmanager.py
+++ b/tests/test_secretsmanager/test_secretsmanager.py
@@ -38,7 +38,11 @@ def test_get_secret_value_binary():
 def test_get_secret_that_does_not_exist():
     conn = boto3.client('secretsmanager', region_name='us-west-2')
 
-    with assert_raises(ClientError):
+    with assert_raises_regexp(
+            ClientError,
+            r"An error occurred \(ResourceNotFoundException\) when calling the GetSecretValue "
+            r"operation: Secrets Manager can’t find the specified secret."
+    ):
         result = conn.get_secret_value(SecretId='i-dont-exist')
 
 
@@ -48,7 +52,11 @@ def test_get_secret_that_does_not_match():
     create_secret = conn.create_secret(Name='java-util-test-password',
                                        SecretString="foosecret")
 
-    with assert_raises(ClientError):
+    with assert_raises_regexp(
+            ClientError,
+            r"An error occurred \(ResourceNotFoundException\) when calling the GetSecretValue "
+            r"operation: Secrets Manager can’t find the specified secret."
+    ):
         result = conn.get_secret_value(SecretId='i-dont-match')
 
 
diff --git a/tests/test_secretsmanager/test_server.py b/tests/test_secretsmanager/test_server.py
index 25fc1676b..a1491dc8f 100644
--- a/tests/test_secretsmanager/test_server.py
+++ b/tests/test_secretsmanager/test_server.py
@@ -49,7 +49,7 @@ def test_get_secret_that_does_not_exist():
                                "X-Amz-Target": "secretsmanager.GetSecretValue"},
                            )
     json_data = json.loads(get_secret.data.decode("utf-8"))
-    assert json_data['message'] == "Secrets Manager can't find the specified secret"
+    assert json_data['message'] == "Secrets Manager can’t find the specified secret."
     assert json_data['__type'] == 'ResourceNotFoundException'
 
 @mock_secretsmanager
@@ -70,7 +70,7 @@ def test_get_secret_that_does_not_match():
                                "X-Amz-Target": "secretsmanager.GetSecretValue"},
                            )
     json_data = json.loads(get_secret.data.decode("utf-8"))
-    assert json_data['message'] == "Secrets Manager can't find the specified secret"
+    assert json_data['message'] == "Secrets Manager can’t find the specified secret."
     assert json_data['__type'] == 'ResourceNotFoundException'
 
 @mock_secretsmanager
@@ -178,7 +178,7 @@ def test_describe_secret_that_does_not_exist():
                     )
 
     json_data = json.loads(describe_secret.data.decode("utf-8"))
-    assert json_data['message'] == "Secrets Manager can't find the specified secret"
+    assert json_data['message'] == "Secrets Manager can’t find the specified secret."
     assert json_data['__type'] == 'ResourceNotFoundException'
 
 @mock_secretsmanager
@@ -202,7 +202,7 @@ def test_describe_secret_that_does_not_match():
                     )
 
     json_data = json.loads(describe_secret.data.decode("utf-8"))
-    assert json_data['message'] == "Secrets Manager can't find the specified secret"
+    assert json_data['message'] == "Secrets Manager can’t find the specified secret."
     assert json_data['__type'] == 'ResourceNotFoundException'
 
 @mock_secretsmanager
@@ -303,7 +303,7 @@ def test_rotate_secret_that_does_not_exist():
                     )
 
     json_data = json.loads(rotate_secret.data.decode("utf-8"))
-    assert json_data['message'] == "Secrets Manager can't find the specified secret"
+    assert json_data['message'] == "Secrets Manager can’t find the specified secret."
     assert json_data['__type'] == 'ResourceNotFoundException'
 
 @mock_secretsmanager
@@ -327,7 +327,7 @@ def test_rotate_secret_that_does_not_match():
                     )
 
     json_data = json.loads(rotate_secret.data.decode("utf-8"))
-    assert json_data['message'] == "Secrets Manager can't find the specified secret"
+    assert json_data['message'] == "Secrets Manager can’t find the specified secret."
     assert json_data['__type'] == 'ResourceNotFoundException'
 
 @mock_secretsmanager