diff --git a/modules/ECMGeneratePriFile.cmake b/modules/ECMGeneratePriFile.cmake
--- a/modules/ECMGeneratePriFile.cmake
+++ b/modules/ECMGeneratePriFile.cmake
@@ -159,18 +159,22 @@
   string(REGEX REPLACE "^[0-9]+\\.([0-9]+)\\.[0-9]+.*" "\\1" PROJECT_VERSION_MINOR "${PROJECT_VERSION_STRING}")
   string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" PROJECT_VERSION_PATCH "${PROJECT_VERSION_STRING}")
 
+  # Prepare the right number of "../.." to go from ECM_MKSPECS_INSTALL_DIR to the install prefix
+  # This allows to make the generated pri files relocatable (no absolute paths)
+  string(REGEX REPLACE "[^/]+" ".." PRI_ROOT_RELATIVE_TO_MKSPECS ${ECM_MKSPECS_INSTALL_DIR})
+
   set(PRI_TARGET_BASENAME ${EGPF_BASE_NAME})
   set(PRI_TARGET_LIBNAME ${EGPF_LIB_NAME})
   set(PRI_TARGET_QTDEPS ${EGPF_DEPS})
   if(IS_ABSOLUTE "${EGPF_INCLUDE_INSTALL_DIR}")
       set(PRI_TARGET_INCLUDES "${EGPF_INCLUDE_INSTALL_DIR}")
   else()
-      set(PRI_TARGET_INCLUDES "${CMAKE_INSTALL_PREFIX}/${EGPF_INCLUDE_INSTALL_DIR}")
+      set(PRI_TARGET_INCLUDES "$$PWD/${PRI_ROOT_RELATIVE_TO_MKSPECS}/${EGPF_INCLUDE_INSTALL_DIR}")
   endif()
   if(IS_ABSOLUTE "${EGPF_LIB_INSTALL_DIR}")
       set(PRI_TARGET_LIBS "${EGPF_LIB_INSTALL_DIR}")
   else()
-      set(PRI_TARGET_LIBS "${CMAKE_INSTALL_PREFIX}/${EGPF_LIB_INSTALL_DIR}")
+      set(PRI_TARGET_LIBS "$$PWD/${PRI_ROOT_RELATIVE_TO_MKSPECS}/${EGPF_LIB_INSTALL_DIR}")
   endif()
   set(PRI_TARGET_DEFINES "")