diff --git a/fuzz/fuzz_targets/equivalence_jit.rs b/fuzz/fuzz_targets/equivalence_jit.rs
index 751278b9abb..66e74e9019d 100644
--- a/fuzz/fuzz_targets/equivalence_jit.rs
+++ b/fuzz/fuzz_targets/equivalence_jit.rs
@@ -31,13 +31,12 @@ impl Config for ExportedFunctionConfig {
     }
 }
 
-#[derive(Arbitrary)]
 struct WasmSmithModule(ConfiguredModule<ExportedFunctionConfig>);
-impl Default for WasmSmithModule {
-    fn default() -> Self {
-        let mut inner = ConfiguredModule::<ExportedFunctionConfig>::default();
-        inner.ensure_termination(100000);
-        Self(inner)
+impl<'a> arbitrary::Arbitrary<'a> for WasmSmithModule {
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
+        let mut module = ConfiguredModule::<ExportedFunctionConfig>::arbitrary(u)?;
+        module.ensure_termination(100000);
+        Ok(WasmSmithModule(module))
     }
 }
 impl std::fmt::Debug for WasmSmithModule {
diff --git a/fuzz/fuzz_targets/jit_cranelift.rs b/fuzz/fuzz_targets/jit_cranelift.rs
index 6f7bb4afc14..26eb9f7f4e0 100644
--- a/fuzz/fuzz_targets/jit_cranelift.rs
+++ b/fuzz/fuzz_targets/jit_cranelift.rs
@@ -20,7 +20,7 @@ impl Config for NoImportsConfig {
         false
     }
 }
-#[derive(Default, Arbitrary)]
+#[derive(Arbitrary)]
 struct WasmSmithModule(ConfiguredModule<NoImportsConfig>);
 impl std::fmt::Debug for WasmSmithModule {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
diff --git a/fuzz/fuzz_targets/jit_llvm.rs b/fuzz/fuzz_targets/jit_llvm.rs
index badf65d9faa..7885485e3df 100644
--- a/fuzz/fuzz_targets/jit_llvm.rs
+++ b/fuzz/fuzz_targets/jit_llvm.rs
@@ -20,7 +20,7 @@ impl Config for NoImportsConfig {
         false
     }
 }
-#[derive(Default, Arbitrary)]
+#[derive(Arbitrary)]
 struct WasmSmithModule(ConfiguredModule<NoImportsConfig>);
 impl std::fmt::Debug for WasmSmithModule {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
diff --git a/fuzz/fuzz_targets/jit_singlepass.rs b/fuzz/fuzz_targets/jit_singlepass.rs
index 163b1e911fa..94a7a0448ea 100644
--- a/fuzz/fuzz_targets/jit_singlepass.rs
+++ b/fuzz/fuzz_targets/jit_singlepass.rs
@@ -20,7 +20,7 @@ impl Config for NoImportsConfig {
         false
     }
 }
-#[derive(Default, Arbitrary)]
+#[derive(Arbitrary)]
 struct WasmSmithModule(ConfiguredModule<NoImportsConfig>);
 impl std::fmt::Debug for WasmSmithModule {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
diff --git a/fuzz/fuzz_targets/metering.rs b/fuzz/fuzz_targets/metering.rs
index 3262ca995b1..6f5e56e5243 100644
--- a/fuzz/fuzz_targets/metering.rs
+++ b/fuzz/fuzz_targets/metering.rs
@@ -24,7 +24,7 @@ impl Config for NoImportsConfig {
     }
 }
 
-#[derive(Default, Arbitrary)]
+#[derive(Arbitrary)]
 struct WasmSmithModule(ConfiguredModule<NoImportsConfig>);
 impl std::fmt::Debug for WasmSmithModule {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
diff --git a/fuzz/fuzz_targets/native_cranelift.rs b/fuzz/fuzz_targets/native_cranelift.rs
index 06e688fde6a..1be7c5e17c3 100644
--- a/fuzz/fuzz_targets/native_cranelift.rs
+++ b/fuzz/fuzz_targets/native_cranelift.rs
@@ -20,7 +20,7 @@ impl Config for NoImportsConfig {
         false
     }
 }
-#[derive(Default, Arbitrary)]
+#[derive(Arbitrary)]
 struct WasmSmithModule(ConfiguredModule<NoImportsConfig>);
 impl std::fmt::Debug for WasmSmithModule {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {