diff --git a/.github/workflows/test-build.yml b/.github/workflows/test-build.yml
index 33205aa83..566aad3c7 100644
--- a/.github/workflows/test-build.yml
+++ b/.github/workflows/test-build.yml
@@ -93,7 +93,7 @@ jobs:
         shell: bash
         run: |
           rm -rf build
-          cmake -B build . -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release -DYOSYS_COMPILER_LAUNCHER=ccache
+          cmake -B build . -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release -DYOSYS_COMPILER_LAUNCHER=ccache -DYOSYS_USE_BUNDLED_LIBS=ON
           cmake --build build -j$procs
           ctest --test-dir build/tests/unit
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index bb3766fd7..3745ea0fe 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,6 +57,8 @@ option(YOSYS_WITHOUT_SLANG "Disable Slang integration" OFF)
 option(YOSYS_WITHOUT_TCL "Disable Tcl integration" OFF)
 option(YOSYS_WITH_PYTHON "Enable Python integration" OFF)
 
+option(YOSYS_USE_BUNDLED_LIBS "Use bundled third-party libraries" OFF)
+
 set(YOSYS_VERIFIC_DIR "" CACHE FILEPATH "Path to the Verific source code (empty to disable)")
 set(YOSYS_VERIFIC_COMPONENTS "" CACHE STRING
 	"List of Verific components to link (empty for autodetect)")
diff --git a/libs/CMakeLists.txt b/libs/CMakeLists.txt
index 385425af2..cb81b3af2 100644
--- a/libs/CMakeLists.txt
+++ b/libs/CMakeLists.txt
@@ -12,7 +12,9 @@ block()
     include(FetchContent)
     set(FETCHCONTENT_FULLY_DISCONNECTED ON)
 
-    find_package(fmt 12.2 QUIET)
+    if(NOT YOSYS_USE_BUNDLED_LIBS)
+        find_package(fmt 12.2 QUIET)
+    endif()
     if(fmt_FOUND)
         set(SLANG_USE_SYSTEM_FMT ON)
     else()
@@ -25,7 +27,9 @@ block()
         FetchContent_MakeAvailable(fmt)
     endif()
 
-    find_package(tomlplusplus 3.4 QUIET)
+    if(NOT YOSYS_USE_BUNDLED_LIBS)
+        find_package(tomlplusplus 3.4 QUIET)
+    endif()
     if(tomlplusplus_FOUND)
         set(SLANG_USE_SYSTEM_TOMLPLUSPLUS ON)
     else()
@@ -37,7 +41,9 @@ block()
         FetchContent_MakeAvailable(tomlplusplus)
     endif()
 
-    find_package(Boost 1.87.0 CONFIG QUIET)
+    if(NOT YOSYS_USE_BUNDLED_LIBS)
+        find_package(Boost 1.87.0 CONFIG QUIET)
+    endif()
     if(Boost_FOUND)
         set(SLANG_USE_SYSTEM_BOOST ON)
     else()