diff --git a/include/mbedtls/build_info.h b/include/mbedtls/build_info.h
index 4835beb..86a3e16 100644
--- a/include/mbedtls/build_info.h
+++ b/include/mbedtls/build_info.h
@@ -87,6 +87,12 @@
 #define MBEDTLS_MD_LIGHT
 #endif
 
+/* Auto-enable MBEDTLS_MD_LIGHT it one module needs it.
+ */
+#if defined(MBEDTLS_PEM_PARSE_C)
+#define MBEDTLS_MD_LIGHT
+#endif
+
 /* If MBEDTLS_PSA_CRYPTO_C is defined, make sure MBEDTLS_PSA_CRYPTO_CLIENT
  * is defined as well to include all PSA code.
  */