diff --git a/library/aesce.c b/library/aesce.c
index 1a0db163d..64f4b2b68 100644
--- a/library/aesce.c
+++ b/library/aesce.c
@@ -385,8 +385,8 @@ static inline uint8x16_t pmull_low(uint8x16_t a, uint8x16_t b)
 
     return vreinterpretq_u8_p128(
         MBEDTLS_VMULL_P64(
-            vget_low_p64(vreinterpretq_p64_u8(a)),
-            vget_low_p64(vreinterpretq_p64_u8(b))
+            (poly64_t) vget_low_p64(vreinterpretq_p64_u8(a)),
+            (poly64_t) vget_low_p64(vreinterpretq_p64_u8(b))
             ));
 }