diff --git a/src/tools/miri/tests/native-lib/scalar_arguments.c b/src/tools/miri/tests/native-lib/scalar_arguments.c
index acccf06f3df2..8cf38f74413c 100644
--- a/src/tools/miri/tests/native-lib/scalar_arguments.c
+++ b/src/tools/miri/tests/native-lib/scalar_arguments.c
@@ -22,11 +22,11 @@ EXPORT uint32_t get_unsigned_int(void) {
   return -10;
 }
 
-EXPORT short add_int16(int16_t x) {
+EXPORT int16_t add_int16(int16_t x) {
   return x + 3;
 }
 
-EXPORT long add_short_to_long(int16_t x, int64_t y) {
+EXPORT int64_t add_short_to_long(int16_t x, int64_t y) {
   return x + y;
 }