Add fuzz target for `Weight`

diff --git a/.github/workflows/cron-daily-fuzz.yml b/.github/workflows/cron-daily-fuzz.yml
index a6bc7252..1b65ff00 100644
--- a/.github/workflows/cron-daily-fuzz.yml
+++ b/.github/workflows/cron-daily-fuzz.yml
@@ -35,6 +35,7 @@ jobs:
           hashes_sha256,
           hashes_sha512,
           hashes_sha512_256,
+          units_arbitrary_weight,
           units_parse_amount,
         ]
     steps:
diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index e2e955e6..27d23705 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -89,6 +89,10 @@ path = "fuzz_targets/hashes/sha512.rs"
 name = "hashes_sha512_256"
 path = "fuzz_targets/hashes/sha512_256.rs"
 
+[[bin]]
+name = "units_arbitrary_weight"
+path = "fuzz_targets/units/arbitrary_weight.rs"
+
 [[bin]]
 name = "units_parse_amount"
 path = "fuzz_targets/units/parse_amount.rs"
diff --git a/fuzz/fuzz_targets/units/arbitrary_weight.rs b/fuzz/fuzz_targets/units/arbitrary_weight.rs
new file mode 100644
index 00000000..4fe66fed
--- /dev/null
+++ b/fuzz/fuzz_targets/units/arbitrary_weight.rs
@@ -0,0 +1,87 @@
+use arbitrary::{Arbitrary, Unstructured};
+use honggfuzz::fuzz;
+use bitcoin::Weight;
+
+fn do_test(data: &[u8]) {
+    let mut u = Unstructured::new(data);
+    let w = Weight::arbitrary(&mut u);
+
+    if let Ok(weight) = w {
+        weight.to_wu();
+        weight.to_kwu_ceil();
+        weight.to_kwu_floor();
+        weight.to_vbytes_ceil();
+        weight.to_vbytes_floor();
+
+        // Operations that take u64 as the rhs
+        for operation in [Weight::checked_mul, Weight::checked_div] {
+            if let Ok(val) = u.arbitrary() {
+                let _ = operation(weight, val);
+            } else {
+                return;
+            }
+        }
+
+        // Operations that take Weight as the rhs
+        for operation in [Weight::checked_add, Weight::checked_sub] {
+            if let Ok(val) = u.arbitrary() {
+                let _ = operation(weight, val);
+            } else {
+                return;
+            }
+        }
+    }
+
+    // Constructors that return a Weight
+    for constructor in [Weight::from_wu, Weight::from_witness_data_size,  Weight::from_non_witness_data_size] {
+        if let Ok(val) = u.arbitrary() {
+            constructor(val);
+        } else {
+            return;
+        }
+    }
+
+    // Constructors that return an Option<Weight>
+    for constructor in [Weight::from_vb, Weight::from_kwu] {
+        if let Ok(val) = u.arbitrary() {
+            constructor(val);
+        } else {
+            return;
+        }
+    }
+}
+
+fn main() {
+    loop {
+        fuzz!(|data| {
+            do_test(data);
+        });
+    }
+}
+
+#[cfg(all(test, fuzzing))]
+mod tests {
+    fn extend_vec_from_hex(hex: &str, out: &mut Vec<u8>) {
+        let mut b = 0;
+        for (idx, c) in hex.as_bytes().iter().enumerate() {
+            b <<= 4;
+            match *c {
+                b'A'..=b'F' => b |= c - b'A' + 10,
+                b'a'..=b'f' => b |= c - b'a' + 10,
+                b'0'..=b'9' => b |= c - b'0',
+                _ => panic!("Bad hex"),
+            }
+            if (idx & 1) == 1 {
+                out.push(b);
+                b = 0;
+            }
+        }
+    }
+
+    #[test]
+    fn duplicate_crash() {
+        let mut a = Vec::new();
+        extend_vec_from_hex("00", &mut a);
+        super::do_test(&a);
+    }
+}