diff --git a/Cargo.toml b/Cargo.toml
index 8636385..2e2e34a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -53,6 +53,7 @@ zeroize = { version = "1", default-features = false }
 fiat-crypto = { version = "0.1.6", optional = true}
 
 # Betrusted/Precursor dependency set
+log = {version = "0.4", optional = true}
 [dependencies.engine-25519]
 git="https://github.com/betrusted-io/xous-engine-25519.git"
 rev="63d3d1f30736022e791deaacf4dd62c00b42fe2e"
@@ -89,6 +90,6 @@ simd_backend = ["nightly", "u64_backend", "packed_simd"]
 # in some future release.
 avx2_backend = ["simd_backend"]
 # the betrusted backend uses the curve25519 hardware accelerator in betrusted-soc
-betrusted = ["engine-25519", "engine25519-as"]
+betrusted = ["engine-25519", "engine25519-as", "log"]
 
 [workspace]
\ No newline at end of file
diff --git a/src/montgomery.rs b/src/montgomery.rs
index 1de47be..7266fd2 100644
--- a/src/montgomery.rs
+++ b/src/montgomery.rs
@@ -291,7 +291,7 @@ pub fn differential_add_and_double(
     Q.W = t17;  // W_{Q'} = U_D * 4 (W_P U_Q - U_P W_Q)^2
 }
 
-#[cfg(betrusted)]
+#[cfg(feature = "betrusted")]
 fn copy_to_rf(bytes: [u8; 32], register: usize, rf: &mut [u32; engine_25519::RF_SIZE_IN_U32]) {
     use core::convert::TryInto;
     for (byte, rf_dst) in bytes.chunks_exact(4).zip(rf[register * 8..(register+1)*8].iter_mut()) {
@@ -299,7 +299,7 @@ fn copy_to_rf(bytes: [u8; 32], register: usize, rf: &mut [u32; engine_25519::RF_
     }
 }
 
-#[cfg(betrusted)]
+#[cfg(feature = "betrusted")]
 fn copy_from_rf(register: usize, rf: &[u32; engine_25519::RF_SIZE_IN_U32]) -> [u8; 32] {
     let mut ret: [u8; 32] = [0; 32];
 
@@ -312,7 +312,7 @@ fn copy_from_rf(register: usize, rf: &[u32; engine_25519::RF_SIZE_IN_U32]) -> [u
     ret
 }
 
-#[cfg(betrusted)]
+#[cfg(feature = "betrusted")]
 pub fn differential_add_and_double_hw(
     P: &mut ProjectivePoint,
     Q: &mut ProjectivePoint,
@@ -444,8 +444,9 @@ impl<'a, 'b> Mul<&'b Scalar> for &'a MontgomeryPoint {
     type Output = MontgomeryPoint;
 
     /// Given `self` \\( = u\_0(P) \\), and a `Scalar` \\(n\\), return \\( u\_0([n]P) \\).
-    #[cfg(betrusted)]
+    #[cfg(feature = "betrusted")]
     fn mul(self, scalar: &'b Scalar) -> MontgomeryPoint {
+        log::debug!("hw mont");
         // Algorithm 8 of Costello-Smith 2017
         let affine_u = FieldElement::from_bytes(&self.0);
         let mut x0 = ProjectivePoint::identity();
@@ -454,7 +455,6 @@ impl<'a, 'b> Mul<&'b Scalar> for &'a MontgomeryPoint {
             W: FieldElement::one(),
         };
 
-
         let mcode = assemble_engine25519!(
             start:
                 // P.U in %20
@@ -633,9 +633,11 @@ impl<'a, 'b> Mul<&'b Scalar> for &'a MontgomeryPoint {
         // curve25519 acceleration!
         x0.to_affine()
     }
-    #[cfg(not(betrusted))]
+    #[cfg(not(feature = "betrusted"))]
     fn mul(self, scalar: &'b Scalar) -> MontgomeryPoint {
         // Algorithm 8 of Costello-Smith 2017
+        #[cfg(not(test))] // due to issue https://github.com/rust-lang/rust/issues/59168, you will have to manually comment this out when running a test on the full system and not just this crate.
+        log::warn!("sw montgomery multiply being used - check for build config errors!");
         let affine_u = FieldElement::from_bytes(&self.0);
         let mut x0 = ProjectivePoint::identity();
         let mut x1 = ProjectivePoint {
diff --git a/src/scalar.rs b/src/scalar.rs
index 773dcb4..05b4381 100644
--- a/src/scalar.rs
+++ b/src/scalar.rs
@@ -822,6 +822,7 @@ impl Scalar {
     }
 
     /// Get the bits of the scalar.
+    #[cfg(not(feature = "betrusted"))]
     pub(crate) fn bits(&self) -> [i8; 256] {
         let mut bits = [0i8; 256];
         for i in 0..256 {