diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index ae3b239f8..6ce4f64c1 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -1252,7 +1252,7 @@ static int ecp_mod_p255(mbedtls_mpi *N)
         return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
     }
     M.p = Mp;
-    memset(Mp, 0, sizeof Mp);
+    memset(Mp, 0, sizeof(Mp));
     memcpy(Mp, N->p + P255_WIDTH - 1, M.n * sizeof(mbedtls_mpi_uint));
     MBEDTLS_MPI_CHK(mbedtls_mpi_shift_r(&M, 255 % (8 * sizeof(mbedtls_mpi_uint))));
     M.n++; /* Make room for multiplication by 19 */
diff --git a/tests/suites/test_suite_mdx.function b/tests/suites/test_suite_mdx.function
index 25665cdf7..5e950a198 100644
--- a/tests/suites/test_suite_mdx.function
+++ b/tests/suites/test_suite_mdx.function
@@ -12,8 +12,8 @@ void md2_text(char *text_src_string, data_t *hash)
     unsigned char src_str[100];
     unsigned char output[16];
 
-    memset(src_str, 0x00, sizeof src_str);
-    memset(output, 0x00, sizeof output);
+    memset(src_str, 0x00, sizeof(src_str));
+    memset(output, 0x00, sizeof(output));
 
     strncpy((char *) src_str, text_src_string, sizeof(src_str) - 1);
 
@@ -21,7 +21,7 @@ void md2_text(char *text_src_string, data_t *hash)
     TEST_ASSERT(ret == 0);
 
     TEST_ASSERT(mbedtls_test_hexcmp(output, hash->x,
-                                    sizeof output, hash->len) == 0);
+                                    sizeof(output), hash->len) == 0);
 }
 /* END_CASE */
 
@@ -32,8 +32,8 @@ void md4_text(char *text_src_string, data_t *hash)
     unsigned char src_str[100];
     unsigned char output[16];
 
-    memset(src_str, 0x00, sizeof src_str);
-    memset(output, 0x00, sizeof output);
+    memset(src_str, 0x00, sizeof(src_str));
+    memset(output, 0x00, sizeof(output));
 
     strncpy((char *) src_str, text_src_string, sizeof(src_str) - 1);
 
@@ -41,7 +41,7 @@ void md4_text(char *text_src_string, data_t *hash)
     TEST_ASSERT(ret == 0);
 
     TEST_ASSERT(mbedtls_test_hexcmp(output, hash->x,
-                                    sizeof output, hash->len) == 0);
+                                    sizeof(output), hash->len) == 0);
 }
 /* END_CASE */