diff --git a/src/algorithms/signal_source/adapters/CMakeLists.txt b/src/algorithms/signal_source/adapters/CMakeLists.txt
index de887cf10..bd0fa201a 100644
--- a/src/algorithms/signal_source/adapters/CMakeLists.txt
+++ b/src/algorithms/signal_source/adapters/CMakeLists.txt
@@ -193,7 +193,7 @@ if(ENABLE_AD9361 OR ENABLE_FMCOMMS2 OR ENABLE_PLUTOSDR)
     if(LIBAD9361_VERSION)
         if(LIBAD9361_VERSION VERSION_GREATER 0.1)
             target_compile_definitions(signal_source_adapters
-                PUBLIC -DLIBAD9361_VERSION_GREATER_THAN_01=1
+                PRIVATE -DLIBAD9361_VERSION_GREATER_THAN_01=1
             )
         endif()
     endif()
diff --git a/src/algorithms/signal_source/libs/CMakeLists.txt b/src/algorithms/signal_source/libs/CMakeLists.txt
index daffa40bb..eab25b48a 100644
--- a/src/algorithms/signal_source/libs/CMakeLists.txt
+++ b/src/algorithms/signal_source/libs/CMakeLists.txt
@@ -73,7 +73,7 @@ if(ENABLE_FMCOMMS2 OR ENABLE_AD9361)
     if(LIBAD9361_VERSION)
         if(LIBAD9361_VERSION VERSION_GREATER 0.1)
             target_compile_definitions(signal_source_libs
-                PUBLIC -DLIBAD9361_VERSION_GREATER_THAN_01=1
+                PRIVATE -DLIBAD9361_VERSION_GREATER_THAN_01=1
             )
         endif()
     endif()