diff --git a/tests/ballerina-test-utils/src/main/java/org/ballerinalang/test/BRunUtil.java b/tests/ballerina-test-utils/src/main/java/org/ballerinalang/test/BRunUtil.java
index a2696a12600c..7589d80789e0 100644
--- a/tests/ballerina-test-utils/src/main/java/org/ballerinalang/test/BRunUtil.java
+++ b/tests/ballerina-test-utils/src/main/java/org/ballerinalang/test/BRunUtil.java
@@ -323,6 +323,7 @@ public static ExitDetails run(CompileResult compileResult, List<String> javaOpts
         String classPathString = System.getProperty("java.class.path") + classPath;
         // Create an argument file for Windows to mitigate the long classpath issue.
         if (IS_WINDOWS) {
+            classPathString = classPathString.replace(" ", "%20");
             String classPathArgs = "classPathArgs";
             try {
                 File classPathArgsFile = File.createTempFile(classPathArgs, ".txt");