diff --git a/libafl/src/observers/cmp.rs b/libafl/src/observers/cmp.rs
index 4f0cd4c18d..0ae3cf4db5 100644
--- a/libafl/src/observers/cmp.rs
+++ b/libafl/src/observers/cmp.rs
@@ -37,10 +37,10 @@ impl CmpValues {
 
     pub fn to_u64_tuple(&self) -> Option<(u64, u64)> {
         match self {
-            CmpValues::U8(t) => Some((t.0 as u64, t.1 as u64)),
-            CmpValues::U16(t) => Some((t.0 as u64, t.1 as u64)),
-            CmpValues::U32(t) => Some((t.0 as u64, t.1 as u64)),
-            CmpValues::U64(t) => Some((t.0 as u64, t.1 as u64)),
+            CmpValues::U8(t) => Some((u64::from(t.0), u64::from(t.1))),
+            CmpValues::U16(t) => Some((u64::from(t.0), u64::from(t.1))),
+            CmpValues::U32(t) => Some((u64::from(t.0), u64::from(t.1))),
+            CmpValues::U64(t) => Some((u64::from(t.0), u64::from(t.1))),
             _ => None,
         }
     }