diff --git a/tests/suites/test_suite_x509write.data b/tests/suites/test_suite_x509write.data
index e0dfd0f..ddbac89 100644
--- a/tests/suites/test_suite_x509write.data
+++ b/tests/suites/test_suite_x509write.data
@@ -268,3 +268,52 @@
 
 Check max extension length
 x509_set_extension_length_check:
+
+OID from numeric string - hardware module name
+oid_from_numeric_string:"1.3.6.1.5.5.7.8.4":0:"2B06010505070804"
+
+OID from numeric string - multi-byte subidentifier
+oid_from_numeric_string:"1.1.2108":0:"29903C"
+
+OID from numeric string - second component greater than 39
+oid_from_numeric_string:"2.49.0.0.826.0":0:"81010000863A00"
+
+OID from numeric string - multi-byte first subidentifier
+oid_from_numeric_string:"2.999":0:"8837"
+
+OID from numeric string - empty string input
+oid_from_numeric_string:"":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - first component not a number
+oid_from_numeric_string:"abc.1.2":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - second component not a number
+oid_from_numeric_string:"1.abc.2":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - first component too large
+oid_from_numeric_string:"3.1":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - first component < 2, second > 39
+oid_from_numeric_string:"1.40":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - third component not a number
+oid_from_numeric_string:"1.2.abc":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - non-'.' separator between first and second
+oid_from_numeric_string:"1/2.3.4":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - non-'.' separator between second and third
+oid_from_numeric_string:"1.2/3.4":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - non-'.' separator between third and fourth
+oid_from_numeric_string:"1.2.3/4":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - OID greater than max length (129 components)
+oid_from_numeric_string:"1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1.2.3.4.5.6.7.8.1":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
+OID from numeric string - OID with maximum subidentifier
+oid_from_numeric_string:"2.4294967215":0:"8FFFFFFF7F"
+
+OID from numeric string - OID with overflowing subidentifier
+oid_from_numeric_string:"2.4294967216":MBEDTLS_ERR_ASN1_INVALID_DATA:""
+
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index eb3c2f7..64b4e9e 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -6,6 +6,7 @@
 #include "mbedtls/pem.h"
 #include "mbedtls/oid.h"
 #include "mbedtls/rsa.h"
+#include "mbedtls/asn1.h"
 #include "mbedtls/asn1write.h"
 #include "mbedtls/pk.h"
 #include "mbedtls/psa_util.h"
@@ -761,3 +762,29 @@
     TEST_ASSERT(MBEDTLS_ERR_X509_BAD_INPUT_DATA == ret);
 }
 /* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_X509_USE_C */
+void oid_from_numeric_string(char *oid_str, int error_ret,
+                             data_t *exp_oid_buf)
+{
+    mbedtls_asn1_buf oid = { 0, 0, NULL };
+    mbedtls_asn1_buf exp_oid = { 0, 0, NULL };
+    int ret;
+
+    exp_oid.tag = MBEDTLS_ASN1_OID;
+    exp_oid.p = exp_oid_buf->x;
+    exp_oid.len = exp_oid_buf->len;
+
+    ret = mbedtls_oid_from_numeric_string(&oid, oid_str, strlen(oid_str));
+
+    if (error_ret == 0) {
+        TEST_EQUAL(oid.len, exp_oid.len);
+        TEST_ASSERT(memcmp(oid.p, exp_oid.p, oid.len) == 0);
+        mbedtls_free(oid.p);
+        oid.p = NULL;
+        oid.len = 0;
+    } else {
+        TEST_EQUAL(ret, error_ret);
+    }
+}
+/* END_CASE */