diff --git a/acvm/src/compiler.rs b/acvm/src/compiler.rs
index bb4db27cc..07d103346 100644
--- a/acvm/src/compiler.rs
+++ b/acvm/src/compiler.rs
@@ -11,7 +11,7 @@ use acir::{
 use indexmap::IndexMap;
 use optimizers::GeneralOptimizer;
 use thiserror::Error;
-use transformers::{CSatTransformer, FallbackTransformer, IsOpcodeSupported, R1CSTransformer};
+use transformers::{CSatTransformer, FallbackTransformer, R1CSTransformer};
 
 use self::optimizers::RangeOptimizer;
 use self::optimizers::Simplifier;
@@ -25,7 +25,7 @@ pub enum CompileError {
 pub fn compile(
     acir: Circuit,
     np_language: Language,
-    is_opcode_supported: IsOpcodeSupported,
+    is_opcode_supported: impl Fn(&Opcode) -> bool,
     simplifier: &Simplifier,
 ) -> Result<Circuit, CompileError> {
     // Instantiate the optimizer.
diff --git a/acvm/src/compiler/optimizers/simplify.rs b/acvm/src/compiler/optimizers/simplify.rs
index 5373d128f..3737d1e0c 100644
--- a/acvm/src/compiler/optimizers/simplify.rs
+++ b/acvm/src/compiler/optimizers/simplify.rs
@@ -439,10 +439,7 @@ mod test {
         FieldElement,
     };
 
-    use crate::compiler::{
-        optimizers::Simplifier,
-        transformers::{FallbackTransformer, IsOpcodeSupported},
-    };
+    use crate::compiler::{optimizers::Simplifier, transformers::FallbackTransformer};
 
     #[test]
     fn simplify_test() {
@@ -479,7 +476,7 @@ mod test {
         simplifier.simplify(&mut circuit);
         assert_eq!(circuit.len(), 3);
         assert_eq!(simplifier.solved_gates.len(), 1);
-        let support_all: IsOpcodeSupported = |_| true;
+        let support_all = |_opcode: &Opcode| true;
         let mut acir = Circuit::default();
         acir.opcodes = circuit;
         let acir = FallbackTransformer::transform(acir, support_all, &simplifier).unwrap();
diff --git a/acvm/src/compiler/transformers/fallback.rs b/acvm/src/compiler/transformers/fallback.rs
index b9bc8834e..ca68e9aed 100644
--- a/acvm/src/compiler/transformers/fallback.rs
+++ b/acvm/src/compiler/transformers/fallback.rs
@@ -7,16 +7,13 @@ use acir::{
     BlackBoxFunc,
 };
 
-// A predicate that returns true if the black box function is supported
-pub type IsOpcodeSupported = fn(&Opcode) -> bool;
-
 pub struct FallbackTransformer;
 
 impl FallbackTransformer {
     //ACIR pass which replace unsupported opcodes using arithmetic fallback
     pub fn transform(
         acir: Circuit,
-        is_supported: IsOpcodeSupported,
+        is_supported: impl Fn(&Opcode) -> bool,
         simplifier: &Simplifier,
     ) -> Result<Circuit, CompileError> {
         let mut acir_supported_opcodes = Vec::with_capacity(acir.opcodes.len());
diff --git a/acvm/src/compiler/transformers/mod.rs b/acvm/src/compiler/transformers/mod.rs
index ddc0e3419..e0d690188 100644
--- a/acvm/src/compiler/transformers/mod.rs
+++ b/acvm/src/compiler/transformers/mod.rs
@@ -4,5 +4,4 @@ mod r1cs;
 
 pub use csat::CSatTransformer;
 pub use fallback::FallbackTransformer;
-pub use fallback::IsOpcodeSupported;
 pub use r1cs::R1CSTransformer;
diff --git a/acvm/src/lib.rs b/acvm/src/lib.rs
index d28b6d21f..4e8b0485e 100644
--- a/acvm/src/lib.rs
+++ b/acvm/src/lib.rs
@@ -159,8 +159,8 @@ pub trait ProofSystemCompiler {
     /// if the language and proof system does not line up.
     fn np_language(&self) -> Language;
 
-    // Returns true if the backend supports the selected black box function
-    fn black_box_function_supported(&self, opcode: &BlackBoxFunc) -> bool;
+    // Returns true if the backend supports the selected opcode
+    fn supports_opcode(&self, opcode: &Opcode) -> bool;
 
     /// Returns the number of gates in a circuit
     fn get_exact_circuit_size(&self, circuit: &Circuit) -> Result<u32, Self::Error>;
@@ -222,14 +222,12 @@ pub fn checksum_constraint_system(cs: &Circuit) -> u32 {
 }
 
 #[deprecated(
-    note = "For backwards compatibility, this method allows you to derive _sensible_ defaults for black box function support based on the np language. \n Backends should simply specify what they support."
+    note = "For backwards compatibility, this method allows you to derive _sensible_ defaults for opcode support based on the np language. \n Backends should simply specify what they support."
 )]
 // This is set to match the previous functionality that we had
 // Where we could deduce what opcodes were supported
 // by knowing the np complete language
-pub fn default_is_opcode_supported(
-    language: Language,
-) -> compiler::transformers::IsOpcodeSupported {
+pub fn default_is_opcode_supported(language: Language) -> fn(&Opcode) -> bool {
     // R1CS does not support any of the opcode except Arithmetic by default.
     // The compiler will replace those that it can -- ie range, xor, and
     fn r1cs_is_supported(opcode: &Opcode) -> bool {