diff --git a/nac3core/src/typecheck/type_inferencer/mod.rs b/nac3core/src/typecheck/type_inferencer/mod.rs
index f852fab9..f002eff9 100644
--- a/nac3core/src/typecheck/type_inferencer/mod.rs
+++ b/nac3core/src/typecheck/type_inferencer/mod.rs
@@ -1,6 +1,6 @@
 use std::cell::RefCell;
 use std::collections::HashMap;
-use std::convert::TryInto;
+use std::convert::{TryInto, From};
 use std::iter::once;
 use std::rc::Rc;
 
@@ -17,6 +17,21 @@ use rustpython_parser::ast::{
 #[cfg(test)]
 mod test;
 
+#[derive(PartialEq, Eq, Hash, Copy, Clone, Debug)]
+pub struct CodeLocation {
+    row: usize,
+    col: usize,
+}
+
+impl From<Location> for CodeLocation {
+    fn from(loc: Location) -> CodeLocation {
+        CodeLocation {
+            row: loc.row(),
+            col: loc.column()
+        }
+    }
+}
+
 pub struct PrimitiveStore {
     pub int32: Type,
     pub int64: Type,
@@ -37,6 +52,7 @@ pub struct Inferencer<'a> {
     pub primitives: &'a PrimitiveStore,
     pub virtual_checks: &'a mut Vec<(Type, Type)>,
     pub variable_mapping: HashMap<String, Type>,
+    pub calls: &'a mut HashMap<CodeLocation, Rc<Call>>,
 }
 
 struct NaiveFolder();
@@ -215,6 +231,7 @@ impl<'a> Inferencer<'a> {
             unifier: self.unifier,
             primitives: self.primitives,
             virtual_checks: self.virtual_checks,
+            calls: self.calls,
             variable_mapping,
         };
         let fun = FunSignature {
@@ -257,6 +274,7 @@ impl<'a> Inferencer<'a> {
             virtual_checks: self.virtual_checks,
             variable_mapping,
             primitives: self.primitives,
+            calls: self.calls,
         };
         let elt = new_context.fold_expr(elt)?;
         let generator = generators.pop().unwrap();
@@ -379,6 +397,7 @@ impl<'a> Inferencer<'a> {
             fun: RefCell::new(None),
             ret,
         });
+        self.calls.insert(location.into(), call.clone());
         let call = self.unifier.add_ty(TypeEnum::TCall(vec![call].into()));
         self.unifier.unify(func.custom.unwrap(), call)?;
 
diff --git a/nac3core/src/typecheck/type_inferencer/test.rs b/nac3core/src/typecheck/type_inferencer/test.rs
index 16a5ffff..c1bceed5 100644
--- a/nac3core/src/typecheck/type_inferencer/test.rs
+++ b/nac3core/src/typecheck/type_inferencer/test.rs
@@ -42,6 +42,7 @@ struct TestEnvironment {
     pub id_to_name: HashMap<usize, String>,
     pub identifier_mapping: HashMap<String, Type>,
     pub virtual_checks: Vec<(Type, Type)>,
+    pub calls: HashMap<CodeLocation, Rc<Call>>,
 }
 
 impl TestEnvironment {
@@ -151,12 +152,13 @@ impl TestEnvironment {
             function_data: FunctionData {
                 resolver,
                 bound_variables: Vec::new(),
-                return_type: None
+                return_type: None,
             },
             primitives,
             id_to_name,
             identifier_mapping,
             virtual_checks: Vec::new(),
+            calls: HashMap::new(),
         }
     }
 
@@ -167,6 +169,7 @@ impl TestEnvironment {
             variable_mapping: Default::default(),
             primitives: &mut self.primitives,
             virtual_checks: &mut self.virtual_checks,
+            calls: &mut self.calls,
         }
     }
 }