diff --git a/scalac-scoverage-plugin/src/main/scala/scoverage/Serializer.scala b/scalac-scoverage-plugin/src/main/scala/scoverage/Serializer.scala
index 98667dd0..12f2c49c 100644
--- a/scalac-scoverage-plugin/src/main/scala/scoverage/Serializer.scala
+++ b/scalac-scoverage-plugin/src/main/scala/scoverage/Serializer.scala
@@ -85,7 +85,9 @@ object Serializer {
     new File(dataDir, Constants.CoverageFileName)
 
   def deserialize(file: File): Coverage = {
-    deserialize(Source.fromFile(file)(Codec.UTF8).getLines())
+    val source = Source.fromFile(file)(Codec.UTF8)
+    try deserialize(source.getLines())
+    finally source.close()
   }
 
   def deserialize(lines: Iterator[String]): Coverage = {
diff --git a/scalac-scoverage-plugin/src/main/scala/scoverage/report/ScoverageHtmlWriter.scala b/scalac-scoverage-plugin/src/main/scala/scoverage/report/ScoverageHtmlWriter.scala
index 791d397c..c2fd3721 100644
--- a/scalac-scoverage-plugin/src/main/scala/scoverage/report/ScoverageHtmlWriter.scala
+++ b/scalac-scoverage-plugin/src/main/scala/scoverage/report/ScoverageHtmlWriter.scala
@@ -39,12 +39,16 @@ class ScoverageHtmlWriter(
     val packageFile = new File(outputDir.getAbsolutePath + "/packages.html")
     val overviewFile = new File(outputDir.getAbsolutePath + "/overview.html")
 
-    val index = IOUtils.readStreamAsString(
-      getClass.getResourceAsStream("/scoverage/index.html")
-    )
-    val css = IOUtils.readStreamAsString(
-      getClass.getResourceAsStream("/scoverage/pure-min.css")
-    )
+    val index = {
+      val in = getClass.getResourceAsStream("/scoverage/index.html")
+      try IOUtils.readStreamAsString(in)
+      finally in.close()
+    }
+    val css = {
+      val in = getClass.getResourceAsStream("/scoverage/pure-min.css")
+      try IOUtils.readStreamAsString(in)
+      finally in.close()
+    }
     IOUtils.writeToFile(indexFile, index)
     IOUtils.writeToFile(cssFile, css)
     IOUtils.writeToFile(packageFile, packageList(coverage).toString())