diff --git a/crates/noirc_evaluator/src/ssa_refactor/ir/instruction/call.rs b/crates/noirc_evaluator/src/ssa_refactor/ir/instruction/call.rs
index f12c16065a7..5892d7e272b 100644
--- a/crates/noirc_evaluator/src/ssa_refactor/ir/instruction/call.rs
+++ b/crates/noirc_evaluator/src/ssa_refactor/ir/instruction/call.rs
@@ -167,7 +167,7 @@ fn simplify_bb_func(
         BlackBoxFunc::Blake2s => simplify_hash(dfg, arguments, acvm::blackbox_solver::blake2s),
         BlackBoxFunc::Keccak256 => {
             match (dfg.get_array_constant(arguments[0]), dfg.get_numeric_constant(arguments[1])) {
-                (Some((input, _)), Some(num_bytes)) => {
+                (Some((input, _)), Some(num_bytes)) if array_is_constant(dfg, &input) => {
                     let input_bytes: Vec<u8> = to_u8_vec(dfg, input);
 
                     let num_bytes = num_bytes.to_u128() as usize;
@@ -185,7 +185,7 @@ fn simplify_bb_func(
             }
         }
         BlackBoxFunc::HashToField128Security => match dfg.get_array_constant(arguments[0]) {
-            Some((input, _)) => {
+            Some((input, _)) if array_is_constant(dfg, &input) => {
                 let input_bytes: Vec<u8> = to_u8_vec(dfg, input);
 
                 let field = acvm::blackbox_solver::hash_to_field_128_security(&input_bytes)
@@ -266,13 +266,17 @@ fn to_u8_vec(dfg: &DataFlowGraph, values: im::Vector<Id<Value>>) -> Vec<u8> {
         .collect()
 }
 
+fn array_is_constant(dfg: &DataFlowGraph, values: &im::Vector<Id<Value>>) -> bool {
+    values.iter().all(|value| dfg.get_numeric_constant(*value).is_some())
+}
+
 fn simplify_hash(
     dfg: &mut DataFlowGraph,
     arguments: &[ValueId],
     hash_function: fn(&[u8]) -> Result<[u8; 32], BlackBoxResolutionError>,
 ) -> SimplifyResult {
     match dfg.get_array_constant(arguments[0]) {
-        Some((input, _)) => {
+        Some((input, _)) if array_is_constant(dfg, &input) => {
             let input_bytes: Vec<u8> = to_u8_vec(dfg, input);
 
             let hash = hash_function(&input_bytes)
@@ -309,7 +313,11 @@ fn simplify_signature(
             Some((public_key_y, _)),
             Some((signature, _)),
             Some((hashed_message, _)),
-        ) => {
+        ) if array_is_constant(dfg, &public_key_x)
+            && array_is_constant(dfg, &public_key_y)
+            && array_is_constant(dfg, &signature)
+            && array_is_constant(dfg, &hashed_message) =>
+        {
             let public_key_x: [u8; 32] = to_u8_vec(dfg, public_key_x)
                 .try_into()
                 .expect("ECDSA public key fields are 32 bytes");