diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 29e8be2a..56dd3ed 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -365,7 +365,7 @@
       ovpnlibdesc: mbed TLS 4.
       # versioning=semver-coerced
       ghrepo: Mbed-TLS/mbedtls
-      gitref: v4.0.0
+      gitref: v4.2.0
       libconfigure: cmake -B build -DCMAKE_INSTALL_PREFIX=$LIBPREFIX
       libmake: cmake --build build
       libinstall: sudo cmake --install build
diff --git a/src/openvpn/mbedtls_compat.h b/src/openvpn/mbedtls_compat.h
index 50739b6..ec45a0f 100644
--- a/src/openvpn/mbedtls_compat.h
+++ b/src/openvpn/mbedtls_compat.h
@@ -43,6 +43,7 @@
 #include "crypto_mbedtls_legacy.h"
 #else
 #include <mbedtls/oid.h>
+#include "crypto_mbedtls.h"
 #endif /* MBEDTLS_VERSION_NUMBER < 0x04000000 */
 
 #ifdef HAVE_PSA_CRYPTO_H
@@ -228,6 +229,18 @@
 mbedtls_compat_pk_check_pair(const mbedtls_pk_context *pub, const mbedtls_pk_context *prv)
 {
 #if MBEDTLS_VERSION_NUMBER >= 0x04000000
+    /* work around bug in mbedtls 4.1.0 by adding missing public key information in prv
+     * cf. https://github.com/Mbed-TLS/TF-PSA-Crypto/issues/807 */
+#if MBEDTLS_VERSION_NUMBER >= 0x04010000
+    if (prv->MBEDTLS_PRIVATE(pub_raw_len) == 0)
+    {
+        mbedtls_pk_context *mut_prv = (mbedtls_pk_context *)prv; /* remove const */
+        ASSERT(mbed_ok(psa_export_public_key(mut_prv->MBEDTLS_PRIVATE(priv_id),
+                                             mut_prv->MBEDTLS_PRIVATE(pub_raw),
+                                             sizeof(mut_prv->MBEDTLS_PRIVATE(pub_raw)),
+                                             &mut_prv->MBEDTLS_PRIVATE(pub_raw_len))));
+    }
+#endif
     return mbedtls_pk_check_pair(pub, prv);
 #else
     return mbedtls_pk_check_pair(pub, prv, mbedtls_ctr_drbg_random, rand_ctx_get());