diff --git a/CMakeLists.txt b/CMakeLists.txt
index ad2a2b8aea..936fac8a50 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -106,11 +106,13 @@ file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/zeek-path-dev.csh
      "setenv HILTI_CXX_INCLUDE_DIRS \"`${CMAKE_CURRENT_BINARY_DIR}/hilti-cxx-include-dirs`\"\n")
 
 file(STRINGS "${CMAKE_CURRENT_SOURCE_DIR}/VERSION" VERSION LIMIT_COUNT 1)
-execute_process(COMMAND grep "^#define  *BRO_PLUGIN_API_VERSION"
+execute_process(COMMAND grep "^constexpr int PLUGIN_API_VERSION"
                 INPUT_FILE ${CMAKE_CURRENT_SOURCE_DIR}/src/plugin/Plugin.h
                 OUTPUT_VARIABLE API_VERSION
                 OUTPUT_STRIP_TRAILING_WHITESPACE)
-string(REGEX REPLACE "^#define.*VERSION *" "" API_VERSION "${API_VERSION}")
+
+string(REGEX MATCH "^constexpr int PLUGIN_API_VERSION = ([0-9]+);" API_VERSION "${API_VERSION}")
+set(API_VERSION "${CMAKE_MATCH_1}")
 
 string(REGEX REPLACE "[.-]" " " version_numbers ${VERSION})
 separate_arguments(version_numbers)
diff --git a/src/plugin/Plugin.h b/src/plugin/Plugin.h
index c4f4f901a8..63525d4984 100644
--- a/src/plugin/Plugin.h
+++ b/src/plugin/Plugin.h
@@ -12,10 +12,6 @@
 #include "zeek/ZeekArgs.h"
 #include "zeek/logging/WriterBackend.h"
 
-// Increase this when making incompatible changes to the plugin API. Note
-// that the constant is never used in C code. It's picked up on by CMake.
-#define BRO_PLUGIN_API_VERSION 7
-
 #define BRO_PLUGIN_BRO_VERSION BRO_VERSION_FUNCTION
 
 namespace zeek::threading
@@ -26,6 +22,10 @@ struct Field;
 namespace zeek
 	{
 
+// Increase this when making incompatible changes to the plugin API. Note
+// that the constant is never used in C code. It's picked up on by CMake.
+constexpr int PLUGIN_API_VERSION = 7;
+
 class ODesc;
 class Event;
 class Func;
@@ -1158,3 +1158,8 @@ private:
 
 	} // namespace plugin
 	} // namespace zeek
+
+// Increase this when making incompatible changes to the plugin API. Note
+// that the constant is never used in C code. It's picked up on by CMake.
+constexpr int BRO_PLUGIN_API_VERSION
+	[[deprecated("Remove in v6.1. Use zeek::PLUGIN_API_VERSION")]] = zeek::PLUGIN_API_VERSION;