diff --git a/NEWS b/NEWS
index d89a3034..9b731ab9 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,6 @@
 * Version 1.4.1 (unreleased)
 - The bundled inih was updated to r62.
+- The bundled protobuf-c was updated to 1.5.2.
 - Fixed a bug where session timeout could be bypassed by reconnecting
   (e.g., closing/opening laptop lid) (#599)
 - occtl: 'show user' command now includes a 'Session started at:' field,
diff --git a/src/protobuf/protobuf-c/protobuf-c.h b/src/protobuf/protobuf-c/protobuf-c.h
index bdc6803a..cb5c82ec 100644
--- a/src/protobuf/protobuf-c/protobuf-c.h
+++ b/src/protobuf/protobuf-c/protobuf-c.h
@@ -795,13 +795,13 @@ protobuf_c_version_number(void);
  * The version of the protobuf-c headers, represented as a string using the same
  * format as protobuf_c_version().
  */
-#define PROTOBUF_C_VERSION		"1.5.1"
+#define PROTOBUF_C_VERSION		"1.5.2"
 
 /**
  * The version of the protobuf-c headers, represented as an integer using the
  * same format as protobuf_c_version_number().
  */
-#define PROTOBUF_C_VERSION_NUMBER	1005001
+#define PROTOBUF_C_VERSION_NUMBER	1005002
 
 /**
  * The minimum protoc-gen-c version which works with the current version of the