diff --git a/src/Bag.php b/src/Bag.php
index 5c4b620..f4f9f19 100644
--- a/src/Bag.php
+++ b/src/Bag.php
@@ -891,7 +891,7 @@ public function setAlgorithms(array $algorithms): void
         $internal_names = array_map(self::class . '::getHashName', $algorithms);
         $valid_algorithms = array_filter($internal_names, [$this, 'hashIsSupported']);
         if (count($valid_algorithms) !== count($algorithms)) {
-            throw new BagItException("One or more of the algorithms provided are supported.");
+            throw new BagItException("One or more of the algorithms provided are NOT supported.");
         }
         $this->setAlgorithmsInternal($valid_algorithms);
     }
@@ -1203,7 +1203,7 @@ public function addTagFile(string $source, string $dest): void
         $this->checkTagFileConstraints($dest);
         $external = $this->makeAbsolute($dest);
         if (file_exists($external)) {
-            throw new BagItException("Tag file ($dest) already exists in the bag, use ->replaceTagFile() to replace.");
+            throw new BagItException("Tag file ($dest) already exists in the bag.");
         }
         $this->setExtended(true);
         $parentDirs = dirname($external);
diff --git a/tests/BagTest.php b/tests/BagTest.php
index 8459645..bd37cd8 100644
--- a/tests/BagTest.php
+++ b/tests/BagTest.php
@@ -583,7 +583,7 @@ public function testSetAlgorithmsFailure(): void
         $bag = Bag::create($this->tmpdir);
         $this->assertArrayEquals(['sha512'], $bag->getAlgorithms());
         $this->expectException(BagItException::class);
-        $this->expectExceptionMessage("One or more of the algorithms provided are supported.");
+        $this->expectExceptionMessage("One or more of the algorithms provided are NOT supported.");
         $bag->setAlgorithms(['sha1', 'SHA-224', "bad-algorithm"]);
     }
 
diff --git a/tests/ExtendedBagTest.php b/tests/ExtendedBagTest.php
index 27c1bc9..b7ac710 100644
--- a/tests/ExtendedBagTest.php
+++ b/tests/ExtendedBagTest.php
@@ -1105,9 +1105,7 @@ public function testAddTagNotOverwrite(): void
         $bag->addTagFile($special_file, 'special.txt');
         $this->assertFileExists($bag->getBagRoot() . '/special.txt');
         $this->expectException(BagItException::class);
-        $this->expectExceptionMessage(
-            "Tag file (special.txt) already exists in the bag, use ->replaceTagFile() to replace."
-        );
+        $this->expectExceptionMessage("Tag file (special.txt) already exists in the bag.");
         $bag->addTagFile($special_file, 'special.txt');
     }