diff --git a/library/bignum.c b/library/bignum.c
index d559c9e..7661dd3 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1706,7 +1706,7 @@
      */
     const size_t x_index = 0;
     mbedtls_mpi_init(&W[x_index]);
-    mbedtls_mpi_copy(&W[x_index], X);
+    MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&W[x_index], X));
 
     j = N->n + 1;
     /* All W[i] and X must have at least N->n limbs for the mpi_montmul()
@@ -1893,7 +1893,7 @@
     /*
      * Load the result in the output variable.
      */
-    mbedtls_mpi_copy(X, &W[x_index]);
+    MBEDTLS_MPI_CHK(mbedtls_mpi_copy(X, &W[x_index]));
 
 cleanup:
 
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 1faec16..6e55f22 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -373,7 +373,7 @@
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     if (rs_ctx != NULL && rs_ctx->sig != NULL) {
-        mbedtls_mpi_copy(r, pr);
+        MBEDTLS_MPI_CHK(mbedtls_mpi_copy(r, pr));
     }
 #endif
 
@@ -447,7 +447,7 @@
     MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(d, data, grp_len));
     MBEDTLS_MPI_CHK(derive_mpi(grp, &h, buf, blen));
     MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&h, data + grp_len, grp_len));
-    mbedtls_hmac_drbg_seed_buf(p_rng, md_info, data, 2 * grp_len);
+    MBEDTLS_MPI_CHK(mbedtls_hmac_drbg_seed_buf(p_rng, md_info, data, 2 * grp_len));
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     if (rs_ctx != NULL && rs_ctx->det != NULL) {
diff --git a/library/rsa_alt_helpers.c b/library/rsa_alt_helpers.c
index 3451469..5cc4636 100644
--- a/library/rsa_alt_helpers.c
+++ b/library/rsa_alt_helpers.c
@@ -126,7 +126,7 @@
     }
 
     for (; attempt < num_primes; ++attempt) {
-        mbedtls_mpi_lset(&K, primes[attempt]);
+        MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&K, primes[attempt]));
 
         /* Check if gcd(K,N) = 1 */
         MBEDTLS_MPI_CHK(mbedtls_mpi_gcd(P, &K, N));