diff --git a/src/FSharpLint.Core/Rules/Conventions/SourceLength/SourceLengthHelper.fs b/src/FSharpLint.Core/Rules/Conventions/SourceLength/SourceLengthHelper.fs
index 7d01a1686..d2735ec43 100644
--- a/src/FSharpLint.Core/Rules/Conventions/SourceLength/SourceLengthHelper.fs
+++ b/src/FSharpLint.Core/Rules/Conventions/SourceLength/SourceLengthHelper.fs
@@ -65,7 +65,7 @@ let checkSourceLengthRule (config:Config) range fileContents errorName (skipRang
             stripMultilineComments sourceCode
 
         let commentLinesCount = 
-            singleLineCommentRegex.Matches(sourceCode).Count
+            singleLineCommentRegex.Count(sourceCode)
 
         let sourceCodeLines = sourceCode.Split([| '\n'; '\r' |]) 
         let blankLinesCount =