diff --git a/library/x509_crt.c b/library/x509_crt.c
index be2e526..47745a7 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1425,6 +1425,17 @@
         }
 
         /*
+         * Check if the CA is configured to sign CRLs
+         */
+#if defined(POLARSSL_X509_CHECK_KEY_USAGE)
+        if( x509_crt_check_key_usage( ca, KU_CRL_SIGN ) != 0 )
+        {
+            flags |= BADCRL_NOT_TRUSTED;
+            break;
+        }
+#endif
+
+        /*
          * Check if CRL is correctly signed by the trusted CA
          */
         md_info = md_info_from_type( crl_list->sig_md );
@@ -1548,6 +1559,11 @@
             continue;
         }
 
+#if defined(POLARSSL_X509_CHECK_KEY_USAGE)
+        if( x509_crt_check_key_usage( parent, KU_KEY_CERT_SIGN ) != 0 )
+            continue;
+#endif
+
         /* If we get there, we found a suitable parent */
         break;
     }
@@ -1599,6 +1615,14 @@
             continue;
         }
 
+#if defined(POLARSSL_X509_CHECK_KEY_USAGE)
+        if( x509_crt_check_key_usage( trust_ca, KU_KEY_CERT_SIGN ) != 0 )
+        {
+            trust_ca = trust_ca->next;
+            continue;
+        }
+#endif
+
         /*
          * Reduce path_len to check against if top of the chain is
          * the same as the trusted CA
diff --git a/tests/data_files/test-ca2.ku-crl.crt b/tests/data_files/test-ca2.ku-crl.crt
new file mode 100644
index 0000000..4fb4083
--- /dev/null
+++ b/tests/data_files/test-ca2.ku-crl.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/data_files/test-ca2.ku-crt.crt b/tests/data_files/test-ca2.ku-crt.crt
new file mode 100644
index 0000000..edacc64
--- /dev/null
+++ b/tests/data_files/test-ca2.ku-crt.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/data_files/test-ca2.ku-crt_crl.crt b/tests/data_files/test-ca2.ku-crt_crl.crt
new file mode 100644
index 0000000..ac74e40
--- /dev/null
+++ b/tests/data_files/test-ca2.ku-crt_crl.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/data_files/test-ca2.ku-ds.crt b/tests/data_files/test-ca2.ku-ds.crt
new file mode 100644
index 0000000..c28e17b
--- /dev/null
+++ b/tests/data_files/test-ca2.ku-ds.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index b1cf1c7..8b1df44 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -442,6 +442,26 @@
 depends_on:POLARSSL_PEM_PARSE_C:POLARSSL_ECDSA_C:POLARSSL_RSA_C:POLARSSL_ECP_DP_SECP192R1_ENABLED:POLARSSL_PKCS1_V15
 x509_verify:"data_files/server2.crt":"data_files/test-ca_cat21.crt":"data_files/crl.pem":"NULL":0:0:"NULL"
 
+X509 Certificate verification #52 (CA keyUsage valid)
+depends_on:POLARSSL_PEM_PARSE_C:POLARSSL_ECDSA_C:POLARSSL_SHA256_C
+x509_verify:"data_files/server5.crt":"data_files/test-ca2.ku-crt_crl.crt":"data_files/crl-ec-sha256.pem":"NULL":0:0:"NULL"
+
+X509 Certificate verification #53 (CA keyUsage missing cRLSign)
+depends_on:POLARSSL_PEM_PARSE_C:POLARSSL_ECDSA_C:POLARSSL_SHA256_C
+x509_verify:"data_files/server5.crt":"data_files/test-ca2.ku-crt.crt":"data_files/crl-ec-sha256.pem":"NULL":POLARSSL_ERR_X509_CERT_VERIFY_FAILED:BADCRL_NOT_TRUSTED:"NULL"
+
+X509 Certificate verification #54 (CA keyUsage missing cRLSign, no CRL)
+depends_on:POLARSSL_PEM_PARSE_C:POLARSSL_ECDSA_C:POLARSSL_SHA256_C
+x509_verify:"data_files/server5.crt":"data_files/test-ca2.ku-crt.crt":"data_files/crl.pem":"NULL":0:0:"NULL"
+
+X509 Certificate verification #55 (CA keyUsage missing keyCertSign)
+depends_on:POLARSSL_PEM_PARSE_C:POLARSSL_ECDSA_C:POLARSSL_SHA256_C
+x509_verify:"data_files/server5.crt":"data_files/test-ca2.ku-crl.crt":"data_files/crl-ec-sha256.pem":"NULL":POLARSSL_ERR_X509_CERT_VERIFY_FAILED:BADCERT_NOT_TRUSTED:"NULL"
+
+X509 Certificate verification #55 (CA keyUsage plain wrong)
+depends_on:POLARSSL_PEM_PARSE_C:POLARSSL_ECDSA_C:POLARSSL_SHA256_C
+x509_verify:"data_files/server5.crt":"data_files/test-ca2.ku-ds.crt":"data_files/crl-ec-sha256.pem":"NULL":POLARSSL_ERR_X509_CERT_VERIFY_FAILED:BADCERT_NOT_TRUSTED:"NULL"
+
 X509 Parse Selftest
 depends_on:POLARSSL_MD5_C:POLARSSL_PEM_PARSE_C
 x509_selftest: