diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,12 +1,13 @@
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake-paths.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/cmake-paths.h)
+
 add_library(KF5Purpose
     pluginbase.cpp
     job.cpp
     alternativesmodel.cpp
     configuration.cpp
     helper.cpp
     externalprocess/processjob.cpp
 )
-set_source_files_properties(externalprocess/processjob.cpp PROPERTIES COMPILE_FLAGS "-DCMAKE_INSTALL_FULL_LIBEXECDIR_KF5='\"${CMAKE_INSTALL_FULL_LIBEXECDIR_KF5}\"'")
 
 target_include_directories(KF5Purpose PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>"
                                              "$<BUILD_INTERFACE:${Purpose_BINARY_DIR}>"
diff --git a/src/cmake-paths.h.cmake b/src/cmake-paths.h.cmake
new file mode 100644
--- /dev/null
+++ b/src/cmake-paths.h.cmake
@@ -0,0 +1 @@
+#define CMAKE_INSTALL_FULL_LIBEXECDIR_KF5 "@CMAKE_INSTALL_FULL_LIBEXECDIR_KF5@"
diff --git a/src/externalprocess/processjob.cpp b/src/externalprocess/processjob.cpp
--- a/src/externalprocess/processjob.cpp
+++ b/src/externalprocess/processjob.cpp
@@ -16,6 +16,7 @@
 */
 
 #include "processjob.h"
+#include "cmake-paths.h"
 #include <QLibrary>
 #include <KRandom>
 #include <QMetaMethod>