--- gnuradio-3.7.7.1.orig/CMakeLists.txt
+++ gnuradio-3.7.7.1/CMakeLists.txt
@@ -149,7 +149,9 @@
 set(GR_DATA_DIR         share)
 set(GR_PKG_DATA_DIR     ${GR_DATA_DIR}/${CMAKE_PROJECT_NAME})
 set(GR_DOC_DIR          ${GR_DATA_DIR}/doc)
-set(GR_PKG_DOC_DIR      ${GR_DOC_DIR}/${CMAKE_PROJECT_NAME}-${DOCVER})
+if(NOT DEFINED GR_PKG_DOC_DIR)
+    set(GR_PKG_DOC_DIR      ${GR_DOC_DIR}/${CMAKE_PROJECT_NAME}-${DOCVER})
+endif(NOT DEFINED GR_PKG_DOC_DIR)
 set(GR_CONF_DIR         etc)
 set(GR_PKG_CONF_DIR     ${GR_CONF_DIR}/${CMAKE_PROJECT_NAME}/conf.d)
 set(GR_LIBEXEC_DIR      libexec)