diff --git a/src/rust-jobs/mock-test1/lib.rs b/src/rust-jobs/mock-test1/lib.rs
index 4fe0fb2..816024b 100644
--- a/src/rust-jobs/mock-test1/lib.rs
+++ b/src/rust-jobs/mock-test1/lib.rs
@@ -12,7 +12,7 @@ pub trait Test {
 }
 
 fn test<T: Test>(mock_test: &T, x: i32, y: bool) -> i32 {
-    let ans = mock_test.a(x, y);
+    let ans = mock_test.a(x + 5, y);
     mock_test.b();
     mock_test.c();
     return ans;
@@ -25,17 +25,19 @@ pub extern "C" fn entrypt() {
     let y: bool = verifier::any!();
 
     verifier::assume!(x < 10);
+    verifier::assume!(y == true);
 
     mock
         .times_a(2)
         .times_b(2)
         .times_c(1)
+        .with_a((WithVal::Lt(15), WithVal::Eq(true)))
         .returning_a(|x, _y| x + 5)
         .returning_b(|| 4);
     
     verifier::vassert!(mock.a(x, y) < 15);
     verifier::vassert!(mock.b() == 4);
-    verifier::vassert!(test(&mock, x, y) < 15);
+    verifier::vassert!(test(&mock, x, y) < 20);
     verifier::vassert!(mock.expect_times_a(2));
     verifier::vassert!(mock.expect_times_b(2));
     verifier::vassert!(mock.expect_times_c(1));
diff --git a/src/seamock-lib/src/lib.rs b/src/seamock-lib/src/lib.rs
index ea1fe4f..a3f715b 100644
--- a/src/seamock-lib/src/lib.rs
+++ b/src/seamock-lib/src/lib.rs
@@ -35,9 +35,9 @@ pub fn seamock(_args: TokenStream, input: TokenStream) -> TokenStream {
         generate_attr_names(method, &["times"])
     });
 
-    let mut returning_attrs = vec!{};
-    let mut with_attrs = vec!{};
-    let mut with_methods = vec!{};
+    let mut returning_attrs = vec![];
+    let mut with_attrs = vec![];
+    let mut with_methods = vec![];
 
     let ret = trait_methods.clone().flat_map(|method| {
         let method_output = &method.sig.output;
@@ -134,8 +134,7 @@ pub fn seamock(_args: TokenStream, input: TokenStream) -> TokenStream {
         let method_name =  &method.sig.ident;
         let method_output = &method.sig.output;
         let method_inputs = &method.sig.inputs;
-        let mut params = vec!{};
-        // For each argument, create WithVal<T> where T is the argument type
+        let mut params = vec![];
         for arg in method_inputs.iter() {
             if let syn::FnArg::Typed(pat_type) = arg {
                 let arg_name = match &*pat_type.pat {
@@ -149,15 +148,49 @@ pub fn seamock(_args: TokenStream, input: TokenStream) -> TokenStream {
         let times_attr = Ident::new(&format!("times_{}", &method.sig.ident), method.sig.ident.span());
         let max_times_attr = Ident::new(&format!("max_times_{}", &method.sig.ident), method.sig.ident.span());
         let ret_func = Ident::new(&format!("val_returning_{}", &method.sig.ident), method.sig.ident.span());
-        let error = format!("Hit times limit for {}", &method.sig.ident);
+        let max_attr_error = format!("Hit times limit for {}", &method.sig.ident);
+        let val_attr = Ident::new(&format!("val_with_{}", &method.sig.ident), method.sig.ident.span());
+        let val_error = format!("Called {} with incorrect parameters", &method.sig.ident);
+
+        let expected_val_logic = params.iter().enumerate().map(|(i, _)| {
+            let idx = syn::Index::from(i);
+            Some (quote! {
+                let with_val = &tuple.#idx;
+                let input = &params.#idx;
+                val_match = val_match && match with_val {
+                    WithVal::Gt(val) => input > val,
+                    WithVal::Gte(val) => input >= val,
+                    WithVal::Lt(val) => input < val,
+                    WithVal::Lte(val) => input <= val,
+                    WithVal::Eq(val) => input == val,
+                };
+            })
+        });
+
+        let with_matching = if params.len() > 0 {
+            quote! {
+                if let Some(tuple) = &self.#val_attr {
+                    let params = (#(#params)*);
+                    let mut val_match = true;
+                    #(
+                        #expected_val_logic
+                    )*
+                    if !val_match {
+                        sea::sea_printf!(#val_error, &self.#val_attr);
+                        verifier::vassert!(false);
+                    }
+                }
+            }
+        } else { quote! {} };
 
         Some (quote! {
             fn #method_name(#method_inputs) #method_output {
                 self.#times_attr.replace_with(|&mut old| old + 1);
-                if (*self.#times_attr.borrow() > self.#max_times_attr) {
-                    sea::sea_printf!(#error, self.#max_times_attr);
+                if *self.#times_attr.borrow() > self.#max_times_attr {
+                    sea::sea_printf!(#max_attr_error, self.#max_times_attr);
                     verifier::vassert!(false);
                 }
+                #with_matching
                 (self.#ret_func)(#(#params)*)
             }
         })
@@ -220,6 +253,8 @@ pub fn seamock(_args: TokenStream, input: TokenStream) -> TokenStream {
     // Combine the generated tokens
     let expanded = quote! {
         use core::cell::RefCell;
+        #[macro_use]
+        extern crate alloc;
         enum WithVal<T> {
             Gt(T),
             Gte(T),