diff --git a/.github/workflows/mac.yml b/.github/workflows/mac.yml
index e169d439d..39206cc36 100644
--- a/.github/workflows/mac.yml
+++ b/.github/workflows/mac.yml
@@ -39,7 +39,7 @@ jobs:
         run: |
           source .venv/bin/activate
           mkdir build && cd build
-          cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON -DENABLE_QT6=ON -DCMAKE_BUILD_TYPE=Release -DARCH_OPT=nehalem -DDEBUG_OUTPUT=ON -DENABLE_USRP=ON -DENABLE_MIRISDR=OFF -DBUILD_SERVER=OFF -DENABLE_EXTERNAL_LIBRARIES=ON -DBUNDLE=ON -DPKG_CONFIG_USE_CMAKE_PREFIX_PATH=TRUE
+          cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON -DENABLE_QT6=ON -DCMAKE_BUILD_TYPE=Release -DARCH_OPT=nehalem -DDEBUG_OUTPUT=ON -DENABLE_USRP=ON -DENABLE_MIRISDR=OFF -DBUILD_SERVER=OFF -DENABLE_EXTERNAL_LIBRARIES=ON -DBUNDLE=ON -DPKG_CONFIG_USE_CMAKE_PREFIX_PATH=TRUE -DPython3_ROOT_DIR=`pwd`/.venv
       - name: Build SDRangel on Mac
         run: |
           source .venv/bin/activate
@@ -95,7 +95,7 @@ jobs:
           source .venv/bin/activate
           which python3
           mkdir build && cd build
-          cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON -DENABLE_QT6=ON -DCMAKE_BUILD_TYPE=Release -DDEBUG_OUTPUT=ON -DENABLE_USRP=ON -DENABLE_MIRISDR=OFF -DBUILD_SERVER=OFF -DENABLE_EXTERNAL_LIBRARIES=ON -DBUNDLE=ON -DPKG_CONFIG_USE_CMAKE_PREFIX_PATH=TRUE
+          cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON -DENABLE_QT6=ON -DCMAKE_BUILD_TYPE=Release -DDEBUG_OUTPUT=ON -DENABLE_USRP=ON -DENABLE_MIRISDR=OFF -DBUILD_SERVER=OFF -DENABLE_EXTERNAL_LIBRARIES=ON -DBUNDLE=ON -DPKG_CONFIG_USE_CMAKE_PREFIX_PATH=TRUE -DPython3_ROOT_DIR=`pwd`/.venv
       - name: Build SDRangel on Mac
         run: |
           source .venv/bin/activate
diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index 7dade82a9..c66d3a6c8 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -1560,6 +1560,11 @@ if (WIN32 OR APPLE)
         else ()
             set(UHD_PYTHON_ARGS "")
         endif ()
+        if (DEFINED Python3_ROOT_DIR)
+            set(UHD_PYTHON_ARGS "-DPython3_ROOT_DIR=${Python3_ROOT_DIR}")
+        else ()
+            set(UHD_PYTHON_ARGS "")
+        endif ()
         ExternalProject_Add(uhd
                 GIT_REPOSITORY https://github.com/EttusResearch/uhd.git
                 GIT_TAG ${UHD_TAG}