diff --git a/src/algorithms/signal_source/libs/CMakeLists.txt b/src/algorithms/signal_source/libs/CMakeLists.txt
index 4f6f226b1..5a35a7992 100644
--- a/src/algorithms/signal_source/libs/CMakeLists.txt
+++ b/src/algorithms/signal_source/libs/CMakeLists.txt
@@ -61,6 +61,7 @@ include_directories(
      ${CMAKE_CURRENT_SOURCE_DIR}
      ${Boost_INCLUDE_DIRS}
      ${GLOG_INCLUDE_DIRS}
+     ${GFlags_INCLUDE_DIRS}
      ${OPT_DRIVER_INCLUDE_DIRS}
 )