diff --git a/src/java/io/bazel/rulesscala/scalac/ScalacInvoker.java b/src/java/io/bazel/rulesscala/scalac/ScalacInvoker.java
index 0de2a622c..e7ebeaccd 100644
--- a/src/java/io/bazel/rulesscala/scalac/ScalacInvoker.java
+++ b/src/java/io/bazel/rulesscala/scalac/ScalacInvoker.java
@@ -32,6 +32,8 @@ public static ScalacInvokerResults invokeCompiler(CompileOptions ops, String[] c
       } else {
         throw ex;
       }
+    } finally {
+      comp.close();
     }
 
     results.stopTime = System.currentTimeMillis();