diff --git a/CMakeLists.txt b/CMakeLists.txt
index 66350c45..3699522b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,7 +24,7 @@ if(Libmultiprocess_ENABLE_CLANG_TIDY)
   set(CMAKE_CXX_CLANG_TIDY "${CLANG_TIDY_EXECUTABLE}")
 endif()
 
-set(Libmultiprocess_EXTERNAL_MPGEN "" CACHE FILEPATH "If specified, should be full path to an external mpgen binary to use rather than the one built internally.")
+set(MPGEN_EXECUTABLE "" CACHE FILEPATH "If specified, should be full path to an external mpgen binary to use rather than the one built internally.")
 
 include("cmake/compat_config.cmake")
 include("cmake/pthread_checks.cmake")
diff --git a/cmake/TargetCapnpSources.cmake b/cmake/TargetCapnpSources.cmake
index 2c3c42e9..963d67d0 100644
--- a/cmake/TargetCapnpSources.cmake
+++ b/cmake/TargetCapnpSources.cmake
@@ -61,15 +61,15 @@ function(target_capnp_sources target include_prefix)
   )
 
   set(MPGEN_BINARY "")
-  if(Libmultiprocess_EXTERNAL_MPGEN)
-    set(MPGEN_BINARY "${Libmultiprocess_EXTERNAL_MPGEN}")
+  if(MPGEN_EXECUTABLE)
+    set(MPGEN_BINARY "${MPGEN_EXECUTABLE}")
     if(NOT EXISTS "${MPGEN_BINARY}")
-      message(FATAL_ERROR "Libmultiprocess_EXTERNAL_MPGEN: \"${MPGEN_BINARY}\" does not exist.")
+      message(FATAL_ERROR "MPGEN_EXECUTABLE: \"${MPGEN_BINARY}\" does not exist.")
     endif()
   elseif(TARGET Libmultiprocess::multiprocess)
     set(MPGEN_BINARY Libmultiprocess::mpgen)
   else()
-    message(FATAL_ERROR "No usable mpgen. Set Libmultiprocess_EXTERNAL_MPGEN or enable the internal target.")
+    message(FATAL_ERROR "No usable mpgen. Set MPGEN_EXECUTABLE or enable the internal target.")
   endif()
 
   set(generated_headers "")