diff --git a/src/interactive.c b/src/interactive.c
index b37334e..d1b50ba 100644
--- a/src/interactive.c
+++ b/src/interactive.c
@@ -176,6 +176,7 @@ libab_result register_functions(libab* ab) {
     libab_ref_free(&trig_type);
     libab_ref_free(&atan2_type);
     libab_ref_free(&difficult_type);
+    libab_ref_free(&equals_num_type);
     libab_ref_free(&print_num_type);
     libab_ref_free(&print_unit_type);
     libab_ref_free(&print_bool_type);