diff --git a/openbr/openbr.cpp b/openbr/openbr.cpp
index e11acf4..97155ec 100644
--- a/openbr/openbr.cpp
+++ b/openbr/openbr.cpp
@@ -318,7 +318,7 @@ const char *br_version()
 
 void br_slave_process(const char *baseName)
 {
-#ifndef BR_EMBEDDED
+#ifdef BR_WITH_QTNETWORK
     WorkerProcess *worker = new WorkerProcess;
     worker->transform = Globals->algorithm;
     worker->baseName = baseName;
@@ -326,7 +326,7 @@ void br_slave_process(const char *baseName)
     delete worker;
 #else
     (void) baseName;
-    qFatal("br_slave_process not supported in embedded builds!");
+    qFatal("multiprocess support requires building with QtNetwork enabled (set BR_WITH_QTNETWORK in cmake).");
 #endif
 }
 
diff --git a/openbr/plugins/cmake/network.cmake b/openbr/plugins/cmake/network.cmake
index 9842ec8..d05fb99 100644
--- a/openbr/plugins/cmake/network.cmake
+++ b/openbr/plugins/cmake/network.cmake
@@ -7,6 +7,7 @@ if(${BR_WITH_QTNETWORK})
   if(${BR_INSTALL_SHARE})
     install(FILES ${HTTPPARSER_LICENSE} RENAME http-parser DESTINATION share/openbr/licenses)
   endif()
+  add_definitions(-DBR_WITH_QTNETWORK)
 else()
   set(BR_EXCLUDED_PLUGINS ${BR_EXCLUDED_PLUGINS} plugins/core/processwrapper.cpp
                                                  plugins/io/download.cpp