diff --git a/enclave_build/src/main.rs b/enclave_build/src/main.rs
index 52af2265..0a5ac5da 100644
--- a/enclave_build/src/main.rs
+++ b/enclave_build/src/main.rs
@@ -144,6 +144,7 @@ fn main() {
         .read(true)
         .write(true)
         .create(true)
+        .truncate(true)
         .open(output)
         .expect("Failed to create output file");