diff --git a/src/Domain/Common/LineNumber.php b/src/Domain/Common/LineNumber.php
index 23674d55..899b814a 100644
--- a/src/Domain/Common/LineNumber.php
+++ b/src/Domain/Common/LineNumber.php
@@ -31,7 +31,7 @@ class LineNumber
      */
     public function __construct(int $lineNumber)
     {
-        Assert::greaterThan($lineNumber, 0, 'Line number must be positive integer. Got: %s');
+        Assert::greaterThanEq($lineNumber, 0, 'Line number must be positive integer or 0. Got: %s');
         $this->lineNumber = $lineNumber;
     }
 
diff --git a/src/Plugins/GitDiffHistoryAnalyser/DiffHistoryAnalyser.php b/src/Plugins/GitDiffHistoryAnalyser/DiffHistoryAnalyser.php
index 6c3eb324..6902a2e9 100644
--- a/src/Plugins/GitDiffHistoryAnalyser/DiffHistoryAnalyser.php
+++ b/src/Plugins/GitDiffHistoryAnalyser/DiffHistoryAnalyser.php
@@ -55,7 +55,7 @@ public function getPreviousLocation(Location $location): PreviousLocation
             return PreviousLocation::fromLocation($location);
         }
 
-        // If file added then
+        // If file added then this is not in the baseline.
         if ($fileMutation->isAddedFile()) {
             return PreviousLocation::noPreviousLocation();
         }
diff --git a/tests/Unit/Plugins/GitDiffHistoryAnalyser/internal/OriginalLineNameCalculatorTest.php b/tests/Unit/Plugins/GitDiffHistoryAnalyser/internal/OriginalLineNameCalculatorTest.php
index 8e75ce56..f50b1894 100644
--- a/tests/Unit/Plugins/GitDiffHistoryAnalyser/internal/OriginalLineNameCalculatorTest.php
+++ b/tests/Unit/Plugins/GitDiffHistoryAnalyser/internal/OriginalLineNameCalculatorTest.php
@@ -81,4 +81,10 @@ public function testCalculateOriginalLine(int $newLineNumber, ?int $expectedOrig
         $originalLineNumber = OriginalLineNumberCalculator::calculateOriginalLineNumber($this->fileMutation, $newLineNumber);
         $this->assertSame($expectedOriginalLineNumber, $originalLineNumber);
     }
+
+    public function testLineNumber0(): void
+    {
+        $originalLineNumber = OriginalLineNumberCalculator::calculateOriginalLineNumber($this->fileMutation, 0);
+        $this->assertSame(0, $originalLineNumber);
+    }
 }
diff --git a/tests/Unit/Plugins/PhpstanTextResultsParser/PhpstanTextResultsParserTest.php b/tests/Unit/Plugins/PhpstanTextResultsParser/PhpstanTextResultsParserTest.php
index 4a1e6374..b60e7c0f 100644
--- a/tests/Unit/Plugins/PhpstanTextResultsParser/PhpstanTextResultsParserTest.php
+++ b/tests/Unit/Plugins/PhpstanTextResultsParser/PhpstanTextResultsParserTest.php
@@ -46,11 +46,25 @@ public function testConversionFromString(): void
     {
         $analysisResults = $this->phpstanTextResultsParser->convertFromString($this->fileContents, $this->projectRoot);
 
-        $this->assertCount(1, $analysisResults->getAnalysisResults());
+        $this->assertCount(2, $analysisResults->getAnalysisResults());
 
         $result1 = $analysisResults->getAnalysisResults()[0];
 
         $this->assertTrue($result1->isMatch(
+            new Location(
+                new FileName('src/Employee.php'),
+                new LineNumber(0)
+            ),
+            new Type('Class not found and could not be autoloaded.')
+        ));
+        $this->assertSame(
+            'Class Demo\Foo not found and could not be autoloaded.',
+            $result1->getMessage()
+        );
+
+        $result2 = $analysisResults->getAnalysisResults()[1];
+
+        $this->assertTrue($result2->isMatch(
             new Location(
                 new FileName('src/Plugins/PsalmTextResultsParser/PsalmTextResultsParser.php'),
                 new LineNumber(50)
@@ -59,7 +73,7 @@ public function testConversionFromString(): void
         ));
         $this->assertSame(
             'Call to an undefined method DaveLiddament\StaticAnalysisResultsBaseliner\Plugins\PsalmTextResultsParser\PsalmTextResultsParser::processLine().',
-            $result1->getMessage()
+            $result2->getMessage()
         );
     }
 
diff --git a/tests/resources/phpstan/phpstan.txt b/tests/resources/phpstan/phpstan.txt
index 0ba144ae..4a87e3b0 100644
--- a/tests/resources/phpstan/phpstan.txt
+++ b/tests/resources/phpstan/phpstan.txt
@@ -1,3 +1,4 @@
 
 
+/vagrant/static-analysis-baseliner/src/Employee.php:0:Class Demo\Foo not found and could not be autoloaded.
 /vagrant/static-analysis-baseliner/src/Plugins/PsalmTextResultsParser/PsalmTextResultsParser.php:50:Call to an undefined method DaveLiddament\StaticAnalysisResultsBaseliner\Plugins\PsalmTextResultsParser\PsalmTextResultsParser::processLine().