diff --git a/include/custom.h b/include/custom.h
index 2222d9c..ac41239 100644
--- a/include/custom.h
+++ b/include/custom.h
@@ -94,6 +94,10 @@ struct libab_function_s {
      * if it was created via partial application.
      */
     libab_ref_vec params;
+    /**
+     * The scope in which this function was declared.
+     */
+    libab_ref scope;
 };
 
 typedef enum libab_operator_variant_e libab_operator_variant;
@@ -143,18 +147,22 @@ void libab_operator_free(libab_operator* op);
  * Initializes a function with the given internal behavior.
  * @param function the function to initialize.
  * @param fun the function implementation.
+ * @param the parent scope in which this function was declared.
  * @return the result of the initialization.
  */
 libab_result libab_function_init_internal(libab_function* function,
-                                          libab_function_ptr fun);
+                                          libab_function_ptr fun,
+                                          libab_ref* scope);
 /**
  * Initializes a function with the given tree behavior.
  * @param function the function to initialize.
  * @param tree the tree that represents the function's behavior.
+ * @param scope the scope in which this function was declared.
  * @return the result of the initialization.
  */
 libab_result libab_function_init_tree(libab_function* function,
-                                      libab_tree* tree);
+                                      libab_tree* tree,
+                                      libab_ref* scope);
 /**
  * Frees the given function.
  * @param fun the function to free.
diff --git a/include/util.h b/include/util.h
index 936c1cb..51eac55 100644
--- a/include/util.h
+++ b/include/util.h
@@ -96,21 +96,25 @@ libab_result libab_create_value_raw(libab_ref* into, void* data,
  * @param into the reference into which to store the new function.
  * @param free_function the free function used to free function instances.
  * @param fun the function implementation.
+ * @param scope the scope in which this function was declared.
  * @return libab_result the result of any necessary allocations.
  */
 libab_result libab_create_function_internal(libab_ref* into,
                                             void (*free_function)(void*),
-                                            libab_function_ptr fun);
+                                            libab_function_ptr fun,
+                                            libab_ref* scope);
 /**
  * Allocates a function that uses a tree to run.
  * @param into the reference into which to store the new function.
  * @param free_function the free function used to free function instances.
  * @param tree the function implementation.
+ * @param scope the scope in which this function was declared.
  * @return libab_result the result of any necessary allocations.
  */
 libab_result libab_create_function_tree(libab_ref* into,
                                         void (*free_function)(void*),
-                                        libab_tree* tree);
+                                        libab_tree* tree,
+                                        libab_ref* scope);
 /**
  * Creates a function list object, storing it in to the given reference.
  * @param into the reference to store into.
diff --git a/src/custom.c b/src/custom.c
index 119fa78..3da4a9c 100644
--- a/src/custom.c
+++ b/src/custom.c
@@ -32,22 +32,26 @@ void libab_operator_free(libab_operator* op) {
     libab_behavior_free(&op->behavior);
 }
 
-libab_result _function_init(libab_function* function) {
+libab_result _function_init(libab_function* function, libab_ref* scope) {
+    libab_ref_copy(scope, &function->scope);
     return libab_ref_vec_init(&function->params);
 }
 libab_result libab_function_init_internal(libab_function* function,
-                                          libab_function_ptr fun) {
-    libab_result result = _function_init(function);
+                                          libab_function_ptr fun,
+                                          libab_ref* scope) {
+    libab_result result = _function_init(function, scope);
     libab_behavior_init_internal(&function->behavior, fun);
     return result;
 }
 libab_result libab_function_init_tree(libab_function* function,
-                                      libab_tree* tree) {
-    libab_result result = _function_init(function);
+                                      libab_tree* tree,
+                                      libab_ref* scope) {
+    libab_result result = _function_init(function, scope);
     libab_behavior_init_tree(&function->behavior, tree);
     return result;
 }
 void libab_function_free(libab_function* fun) {
     libab_behavior_free(&fun->behavior);
     libab_ref_vec_free(&fun->params);
+    libab_ref_free(&fun->scope);
 }
diff --git a/src/libabacus.c b/src/libabacus.c
index 7026028..5f06a08 100644
--- a/src/libabacus.c
+++ b/src/libabacus.c
@@ -147,10 +147,11 @@ libab_result libab_register_operator_postfix(libab* ab, const char* op,
 }
 
 libab_result _create_value_function_internal(libab_ref* into, libab_ref* type,
-                                             libab_function_ptr func) {
+                                             libab_function_ptr func, 
+                                             libab_ref* scope) {
     libab_ref function_ref;
     libab_result result =
-        libab_create_function_internal(&function_ref, _free_function, func);
+        libab_create_function_internal(&function_ref, _free_function, func, scope);
     libab_ref_null(into);
     if (result == LIBAB_SUCCESS) {
         libab_ref_free(into);
@@ -233,7 +234,7 @@ libab_result libab_register_function(libab* ab, const char* name,
     libab_table_entry* existing_entry;
     libab_ref function_value;
     libab_result result =
-        _create_value_function_internal(&function_value, type, func);
+        _create_value_function_internal(&function_value, type, func, &ab->table);
 
     if (result == LIBAB_SUCCESS) {
         existing_entry = libab_table_search_filter(
diff --git a/src/util.c b/src/util.c
index de1c3ee..2454942 100644
--- a/src/util.c
+++ b/src/util.c
@@ -210,12 +210,13 @@ libab_result libab_create_value_raw(libab_ref* into, void* data,
 
 libab_result libab_create_function_internal(libab_ref* into,
                                             void (*free_function)(void*),
-                                            libab_function_ptr fun) {
+                                            libab_function_ptr fun,
+                                            libab_ref* scope) {
     libab_function* new_function;
     libab_result result = LIBAB_SUCCESS;
 
     if ((new_function = malloc(sizeof(*new_function)))) {
-        result = libab_function_init_internal(new_function, fun);
+        result = libab_function_init_internal(new_function, fun, scope);
     } else {
         result = LIBAB_MALLOC;
     }
@@ -237,12 +238,13 @@ libab_result libab_create_function_internal(libab_ref* into,
 
 libab_result libab_create_function_tree(libab_ref* into,
                                         void (*free_function)(void*),
-                                        libab_tree* tree) {
+                                        libab_tree* tree,
+                                        libab_ref* scope) {
     libab_function* new_function;
     libab_result result = LIBAB_SUCCESS;
 
     if ((new_function = malloc(sizeof(*new_function)))) {
-        result = libab_function_init_tree(new_function, tree);
+        result = libab_function_init_tree(new_function, tree, scope);
     } else {
         result = LIBAB_MALLOC;
     }