diff --git a/src/rust/iced-x86/src/block_enc/block.rs b/src/rust/iced-x86/src/block_enc/block.rs
index 1c6f55c93..a77b6ed63 100644
--- a/src/rust/iced-x86/src/block_enc/block.rs
+++ b/src/rust/iced-x86/src/block_enc/block.rs
@@ -63,7 +63,7 @@ impl Block {
 		if self.valid_data.is_empty() {
 			return Ok(());
 		}
-		for _ in 0..self.valid_data_address_aligned - self.valid_data_address {
+		for _ in 0..self.valid_data_address_aligned.wrapping_sub(self.valid_data_address) {
 			self.encoder.write_byte_internal(0xCC);
 		}
 		match self.alignment {
diff --git a/src/rust/iced-x86/src/block_enc/instr/mod.rs b/src/rust/iced-x86/src/block_enc/instr/mod.rs
index ac91fa187..28632f2d3 100644
--- a/src/rust/iced-x86/src/block_enc/instr/mod.rs
+++ b/src/rust/iced-x86/src/block_enc/instr/mod.rs
@@ -42,7 +42,8 @@ pub(super) trait Instr {
 }
 
 fn correct_diff(in_block: bool, diff: i64, gained: u64) -> i64 {
-	if in_block && diff >= gained as i64 {
+	if in_block && diff >= 0 {
+		debug_assert!(diff as u64 >= gained);
 		diff - gained as i64
 	} else {
 		diff