diff --git a/xds/src/main/java/io/grpc/xds/Bootstrapper.java b/xds/src/main/java/io/grpc/xds/Bootstrapper.java
index 894f73cf77..69c5e5858b 100644
--- a/xds/src/main/java/io/grpc/xds/Bootstrapper.java
+++ b/xds/src/main/java/io/grpc/xds/Bootstrapper.java
@@ -81,7 +81,7 @@ abstract class Bootstrapper {
         }
       }
       if (failToBootstrapException != null) {
-        throw new RuntimeException(failToBootstrapException);
+        throw new IOException(failToBootstrapException);
       }
       return bootstrapInfo;
     }