diff --git a/library/psa_crypto_pake.c b/library/psa_crypto_pake.c
index 541e6c4..870b5b5 100644
--- a/library/psa_crypto_pake.c
+++ b/library/psa_crypto_pake.c
@@ -629,7 +629,7 @@
 
         const psa_pake_primitive_t prim = PSA_PAKE_PRIMITIVE(
                 PSA_PAKE_PRIMITIVE_TYPE_ECC, PSA_ECC_FAMILY_SECP_R1, 256 );
-        if( input_length > PSA_PAKE_INPUT_SIZE( PSA_ALG_JPAKE, prim, step ) )
+        if( input_length > (size_t) PSA_PAKE_INPUT_SIZE( PSA_ALG_JPAKE, prim, step ) )
             return( PSA_ERROR_INVALID_ARGUMENT );
 
         if( operation->state == PSA_PAKE_STATE_SETUP )