diff --git a/compiler/noirc_evaluator/src/ssa/ir/dfg.rs b/compiler/noirc_evaluator/src/ssa/ir/dfg.rs
index 870b5e602f1..d0745019cda 100644
--- a/compiler/noirc_evaluator/src/ssa/ir/dfg.rs
+++ b/compiler/noirc_evaluator/src/ssa/ir/dfg.rs
@@ -344,10 +344,16 @@ impl DataFlowGraph {
     pub(crate) fn get_value_max_num_bits(&self, value: ValueId) -> u32 {
         match self[value] {
             Value::Instruction { instruction, .. } => {
+                let bit_size = self.type_of_value(value).bit_size();
                 if let Instruction::Cast(original_value, _) = self[instruction] {
-                    self.type_of_value(original_value).bit_size()
+                    let original_bit_size = self.type_of_value(original_value).bit_size();
+                    if original_bit_size < bit_size {
+                        original_bit_size
+                    } else {
+                        bit_size
+                    }
                 } else {
-                    self.type_of_value(value).bit_size()
+                    bit_size
                 }
             }
 
diff --git a/compiler/noirc_evaluator/src/ssa/ir/instruction/binary.rs b/compiler/noirc_evaluator/src/ssa/ir/instruction/binary.rs
index e491807995b..c5b8e1c165f 100644
--- a/compiler/noirc_evaluator/src/ssa/ir/instruction/binary.rs
+++ b/compiler/noirc_evaluator/src/ssa/ir/instruction/binary.rs
@@ -174,6 +174,8 @@ impl Binary {
                 if operand_type.is_unsigned() {
                     // If we're comparing a variable against a constant value which lies outside of the range of
                     // values which the variable's type can take, we can assume that the equality will be false.
+                    // When checking the variable's max range we want to make sure to include type information
+                    // from previous casts which tell us whether the variable was cast up from a smaller type.
                     let constant = lhs.or(rhs);
                     let non_constant = if lhs.is_some() { self.rhs } else { self.lhs };
                     if let Some(constant) = constant {