diff --git a/tests/suites/test_suite_bignum.misc.data b/tests/suites/test_suite_bignum.misc.data
index e60331c69f..2e3ff1ecc0 100644
--- a/tests/suites/test_suite_bignum.misc.data
+++ b/tests/suites/test_suite_bignum.misc.data
@@ -94,21 +94,39 @@ mpi_read_binary_le:"0941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e
 Base test mbedtls_mpi_write_binary #1
 mpi_write_binary:"941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"000000000941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":100:0
 
+Test mbedtls_mpi_write_binary #1 (Buffer is larger)
+mpi_write_binary:"123123123123123123123123123":"000123123123123123123123123123":15:0
+
 Test mbedtls_mpi_write_binary #1 (Buffer just fits)
 mpi_write_binary:"123123123123123123123123123":"0123123123123123123123123123":14:0
 
 Test mbedtls_mpi_write_binary #2 (Buffer too small)
 mpi_write_binary:"123123123123123123123123123":"23123123123123123123123123":13:MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL
 
+Test mbedtls_mpi_write_binary: nonzero to NULL
+mpi_write_binary:"01":"":0:MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL
+
+Test mbedtls_mpi_write_binary: 0 to NULL
+mpi_write_binary:"00":"":0:0
+
 Base test mbedtls_mpi_write_binary_le #1
 mpi_write_binary_le:"941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"24448b952fbbef93f89286ba330e62528b151eac265cc8ce3038519d09e148af89288e91f48b41acad55d9dc5e2b18097c106be4ce132721bf6359eaf403e7ff90623e8866ee5c192320418daa682f144adedf84f25de11f49d1fe009d37410900000000":100:0
 
+Test mbedtls_mpi_write_binary_le #1 (Buffer is larger)
+mpi_write_binary_le:"123123123123123123123123123":"233112233112233112233112230100":15:0
+
 Test mbedtls_mpi_write_binary_le #1 (Buffer just fits)
 mpi_write_binary_le:"123123123123123123123123123":"2331122331122331122331122301":14:0
 
 Test mbedtls_mpi_write_binary_le #2 (Buffer too small)
 mpi_write_binary_le:"123123123123123123123123123":"23311223311223311223311223":13:MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL
 
+Test mbedtls_mpi_write_binary_le: nonzero to NULL
+mpi_write_binary_le:"01":"":0:MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL
+
+Test mbedtls_mpi_write_binary_le: 0 to NULL
+mpi_write_binary_le:"00":"":0:0
+
 Base test mbedtls_mpi_read_file #1
 mpi_read_file:"../framework/data_files/mpi_16":"01f55332c3a48b910f9942f6c914e58bef37a47ee45cb164a5b6b8d1006bf59a059c21449939ebebfdf517d2e1dbac88010d7b1f141e997bd6801ddaec9d05910f4f2de2b2c4d714e2c14a72fc7f17aa428d59c531627f09":0