diff --git a/input.cpp b/input.cpp
index 2a9ac010b..d08f9d600 100644
--- a/input.cpp
+++ b/input.cpp
@@ -388,7 +388,7 @@ void input_destroy()
 static wint_t input_exec_binding(const input_mapping_t &m, const wcstring &seq)
 {
     wchar_t code = input_function_get_code(m.command);
-    if (code != -1)
+    if (code != (wchar_t)-1)
     {
         switch (code)
         {