diff --git a/librustzcash-wrapper/src/lib.rs b/librustzcash-wrapper/src/lib.rs
index 04c1139..fbaa5c6 100644
--- a/librustzcash-wrapper/src/lib.rs
+++ b/librustzcash-wrapper/src/lib.rs
@@ -1804,10 +1804,10 @@ pub extern "C" fn rust_wrapper_create_transaction(
     }
     let spend_params_in: Vec<u8> = marshall_from_haskell_var(sapspend, sapspend_len, RW);
     let spend_params_reader = Cursor::new(spend_params_in);
-    let spend_prover = SpendParameters::read(spend_params_reader, true).unwrap();
+    let spend_prover = SpendParameters::read(spend_params_reader, false).unwrap();
     let output_params_in: Vec<u8> = marshall_from_haskell_var(sapoutput, sapoutput_len, RW);
     let output_params_reader = Cursor::new(output_params_in);
-    let output_prover = OutputParameters::read(output_params_reader, true).unwrap();
+    let output_prover = OutputParameters::read(output_params_reader, false).unwrap();
     println!("loaded params");
     let result = if net {
         println!("started main build");