diff --git a/teku/src/main/java/tech/pegasys/teku/cli/subcommand/GenesisCommand.java b/teku/src/main/java/tech/pegasys/teku/cli/subcommand/GenesisCommand.java
index e2bd0ba3f31..13b05d52c72 100644
--- a/teku/src/main/java/tech/pegasys/teku/cli/subcommand/GenesisCommand.java
+++ b/teku/src/main/java/tech/pegasys/teku/cli/subcommand/GenesisCommand.java
@@ -60,9 +60,10 @@ public void generate(
     final Spec spec = networkOptions.getSpec();
     final boolean outputToFile =
         genesisParams.outputFile != null && !genesisParams.outputFile.isBlank();
-    try (final OutputStream fileStream =
-        outputToFile ? new FileOutputStream(genesisParams.outputFile) : System.out) {
+    OutputStream fileStream = System.out;
+    try {
       if (outputToFile) {
+        fileStream = new FileOutputStream(genesisParams.outputFile);
         SUB_COMMAND_LOG.generatingMockGenesis(
             genesisParams.validatorCount, genesisParams.genesisTime);
       }
@@ -82,6 +83,8 @@ public void generate(
       if (outputToFile) {
         SUB_COMMAND_LOG.storingGenesis(genesisParams.outputFile, true);
       }
+    } finally {
+      fileStream.close();
     }
   }