diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index ef9a331..b1cf1c7 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -826,3 +826,28 @@
 
 X509 OID numstring #5 (arithmetic overflow)
 x509_oid_numstr:"2A8648F9F8F7F6F5F4F3F2F1F001":"":100:POLARSSL_ERR_OID_BUF_TOO_SMALL
+
+X509 crt keyUsage #1 (no extension, expected KU)
+x509_check_key_usage:"data_files/server1.crt":KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT:0
+
+X509 crt keyUsage #2 (no extension, suprising KU)
+x509_check_key_usage:"data_files/server1.crt":KU_KEY_CERT_SIGN:0
+
+X509 crt keyUsage #3 (extension present, no KU)
+x509_check_key_usage:"data_files/server1.key_usage.crt":0:0
+
+X509 crt keyUsage #4 (extension present, single KU present)
+x509_check_key_usage:"data_files/server1.key_usage.crt":KU_DIGITAL_SIGNATURE:0
+
+X509 crt keyUsage #5 (extension present, single KU absent)
+x509_check_key_usage:"data_files/server1.key_usage.crt":KU_KEY_CERT_SIGN:POLARSSL_ERR_X509_BAD_INPUT_DATA
+
+X509 crt keyUsage #6 (extension present, combined KU present)
+x509_check_key_usage:"data_files/server1.key_usage.crt":KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT:0
+
+X509 crt keyUsage #7 (extension present, combined KU both absent)
+x509_check_key_usage:"data_files/server1.key_usage.crt":KU_KEY_CERT_SIGN|KU_CRL_SIGN:POLARSSL_ERR_X509_BAD_INPUT_DATA
+
+X509 crt keyUsage #8 (extension present, combined KU one absent)
+x509_check_key_usage:"data_files/server1.key_usage.crt":KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT:POLARSSL_ERR_X509_BAD_INPUT_DATA
+
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index effa4cc..a4b2cf3 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -316,6 +316,21 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:POLARSSL_X509_CRT_PARSE_C */
+void x509_check_key_usage( char *crt_file, int usage, int ret )
+{
+    x509_crt crt;
+
+    x509_crt_init( &crt );
+
+    TEST_ASSERT( x509_crt_parse_file( &crt, crt_file ) == 0 );
+
+    TEST_ASSERT( x509_crt_check_key_usage( &crt, usage ) == ret );
+
+    x509_crt_free( &crt );
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:POLARSSL_X509_CRT_PARSE_C:POLARSSL_SELF_TEST */
 void x509_selftest()
 {