diff --git a/src/parser/instruction/encoding/primary_operand.rs b/src/parser/instruction/encoding/primary_operand.rs
index 84784a5..28ada4a 100644
--- a/src/parser/instruction/encoding/primary_operand.rs
+++ b/src/parser/instruction/encoding/primary_operand.rs
@@ -126,20 +126,21 @@ impl From<SecondaryOperand> for PrimaryOperand {
 }
 
 impl Display for PrimaryOperand {
+    // Turn the operand back into a form which parses into the same type
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            Self::Direct(r) => write!(f, "{r}"),
+            Self::Direct(r) => Display::fmt(r, f),
             Self::Indirect(r) => write!(f, "@{r}"),
             Self::PostInc(r) => write!(f, "@{r}+"),
             Self::Indexed(r, idx) => write!(f, "{idx}({r})"),
             Self::Absolute(n) => write!(f, "&{n}"),
             Self::Immediate(n) => write!(f, "#{n}"),
-            Self::Four => write!(f, "#4"),
-            Self::Eight => write!(f, "#8"),
-            Self::Zero => write!(f, "#0"),
-            Self::One => write!(f, "#1"),
-            Self::Two => write!(f, "#2"),
-            Self::MinusOne => write!(f, "#-1"),
+            Self::Four => Display::fmt("#4", f),
+            Self::Eight => Display::fmt("#8", f),
+            Self::Zero => Display::fmt("#0", f),
+            Self::One => Display::fmt("#1", f),
+            Self::Two => Display::fmt("#2", f),
+            Self::MinusOne => Display::fmt("#-1", f),
         }
     }
 }
diff --git a/src/parser/instruction/encoding/secondary_operand.rs b/src/parser/instruction/encoding/secondary_operand.rs
index f94574a..b393983 100644
--- a/src/parser/instruction/encoding/secondary_operand.rs
+++ b/src/parser/instruction/encoding/secondary_operand.rs
@@ -85,11 +85,11 @@ impl Parsable for SecondaryOperand {
 impl Display for SecondaryOperand {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            Self::Direct(r) => write!(f, "{r}"),
+            Self::Direct(r) => Display::fmt(r, f),
             Self::Indexed(r, idx) => write!(f, "{idx}({r})"),
             Self::Absolute(n) => write!(f, "&{n}"),
-            Self::Zero => write!(f, "#0"),
-            Self::One => write!(f, "#1"),
+            Self::Zero => Display::fmt("#0", f),
+            Self::One => Display::fmt("#1", f),
         }
     }
 }