diff --git a/src/pytrexio.i b/src/pytrexio.i
index c7eea59..5f3a4e1 100644
--- a/src/pytrexio.i
+++ b/src/pytrexio.i
@@ -34,12 +34,12 @@
    num variable is modified by address
 */
 /* Return num variables as part of the output tuple */
-%apply int *OUTPUT { int32_t* const num};
-%apply int *OUTPUT { int64_t* const num};
-%apply int *OUTPUT { int32_t* const num_up};
-%apply int *OUTPUT { int32_t* const num_dn};
-%apply int *OUTPUT { int64_t* const num_up};
-%apply int *OUTPUT { int64_t* const num_dn};
+%apply int32_t *OUTPUT { int32_t* const num};
+%apply int64_t *OUTPUT { int64_t* const num};
+%apply int32_t *OUTPUT { int32_t* const num_up};
+%apply int32_t *OUTPUT { int32_t* const num_dn};
+%apply int64_t *OUTPUT { int64_t* const num_up};
+%apply int64_t *OUTPUT { int64_t* const num_dn};
 %apply float *OUTPUT { float* const num};
 %apply double *OUTPUT { double* const num};
 /* Return TREXIO exit code from trexio_open as part of the output tuple */