diff --git a/3rdparty/everest/CMakeLists.txt b/3rdparty/everest/CMakeLists.txt
index 4ad367e17..ee86f1d7b 100644
--- a/3rdparty/everest/CMakeLists.txt
+++ b/3rdparty/everest/CMakeLists.txt
@@ -11,6 +11,19 @@ target_include_directories(everest
           include/everest/kremlib
           ${MBEDTLS_DIR}/library/)
 
+# Pass-through MBEDTLS_CONFIG_FILE and MBEDTLS_USER_CONFIG_FILE
+# This must be duplicated from library/CMakeLists.txt because
+# everest is not directly linked against any mbedtls targets
+# so does not inherit the compile definitions.
+if(MBEDTLS_CONFIG_FILE)
+    target_compile_definitions(everest
+        PUBLIC MBEDTLS_CONFIG_FILE="${MBEDTLS_CONFIG_FILE}")
+endif()
+if(MBEDTLS_USER_CONFIG_FILE)
+    target_compile_definitions(everest
+        PUBLIC MBEDTLS_USER_CONFIG_FILE="${MBEDTLS_USER_CONFIG_FILE}")
+endif()
+
 if(INSTALL_MBEDTLS_HEADERS)
 
   install(DIRECTORY include/everest
diff --git a/3rdparty/p256-m/CMakeLists.txt b/3rdparty/p256-m/CMakeLists.txt
index 0001dd2a8..7ff13084c 100644
--- a/3rdparty/p256-m/CMakeLists.txt
+++ b/3rdparty/p256-m/CMakeLists.txt
@@ -9,6 +9,19 @@ target_include_directories(p256m
          $<INSTALL_INTERFACE:include>
   PRIVATE ${MBEDTLS_DIR}/library/)
 
+# Pass-through MBEDTLS_CONFIG_FILE and MBEDTLS_USER_CONFIG_FILE
+# This must be duplicated from library/CMakeLists.txt because
+# p256m is not directly linked against any mbedtls targets
+# so does not inherit the compile definitions.
+if(MBEDTLS_CONFIG_FILE)
+    target_compile_definitions(p256m
+        PUBLIC MBEDTLS_CONFIG_FILE="${MBEDTLS_CONFIG_FILE}")
+endif()
+if(MBEDTLS_USER_CONFIG_FILE)
+    target_compile_definitions(p256m
+        PUBLIC MBEDTLS_USER_CONFIG_FILE="${MBEDTLS_USER_CONFIG_FILE}")
+endif()
+
 if(INSTALL_MBEDTLS_HEADERS)
 
   install(DIRECTORY :${CMAKE_CURRENT_SOURCE_DIR}