diff --git a/src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageResultsReader.cs b/src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageResultsReader.cs
index b53be5572f..9f5bdde79b 100644
--- a/src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageResultsReader.cs
+++ b/src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageResultsReader.cs
@@ -52,8 +52,9 @@ namespace ICSharpCode.CodeCoverage
 		
 		CodeCoverageResults ReadCodeCoverageResults(string fileName)
 		{
-			TextReader reader = fileSystem.OpenText(FileName.Create(fileName));
-			return new CodeCoverageResults(reader);
+			using (TextReader reader = fileSystem.OpenText(FileName.Create(fileName))) {
+				return new CodeCoverageResults(reader);
+			}
 		}
 		
 		public IEnumerable<string> GetMissingResultsFiles()
diff --git a/src/AddIns/Analysis/CodeCoverage/Project/Src/RunTestWithCodeCoverageCommand.cs b/src/AddIns/Analysis/CodeCoverage/Project/Src/RunTestWithCodeCoverageCommand.cs
index b60ff8f777..aafd3f7464 100644
--- a/src/AddIns/Analysis/CodeCoverage/Project/Src/RunTestWithCodeCoverageCommand.cs
+++ b/src/AddIns/Analysis/CodeCoverage/Project/Src/RunTestWithCodeCoverageCommand.cs
@@ -119,13 +119,18 @@ namespace ICSharpCode.CodeCoverage
 		
 		void DisplayCodeCoverageResults(CodeCoverageResultsReader coverageResultsReader)
 		{
-			foreach (CodeCoverageResults result in coverageResultsReader.GetResults()) {
+			foreach (CodeCoverageResults result in GetResults(coverageResultsReader)) {
 				DisplayCodeCoverageResults(result);
 			}
 			foreach (string missingFile in coverageResultsReader.GetMissingResultsFiles()) {
 				DisplayNoCodeCoverageResultsGeneratedMessage(missingFile);
 			}
 		}
+
+		IEnumerable<CodeCoverageResults> GetResults(CodeCoverageResultsReader coverageResultsReader)
+		{
+			return SD.MainThread.InvokeIfRequired(() => coverageResultsReader.GetResults().ToList());
+		}
 		
 		void DisplayCodeCoverageResults(CodeCoverageResults results)
 		{