diff --git a/CMakeLists.txt b/CMakeLists.txt
index bb161de8..5fa97e79 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,7 +39,7 @@ execute_process(
 )
 endif()
 
-if((NOT WIN32 OR BASH_VERSION_RESULT EQUAL 0) AND NOT EXISTS ${VCPKG_ROOT})
+if(VCPKG_ROOT AND (NOT WIN32 OR BASH_VERSION_RESULT EQUAL 0) AND NOT EXISTS ${VCPKG_ROOT})
     message(STATUS "vcpkg will be cloned into ${VCPKG_ROOT}")
     execute_process(
         #TODO: have the same for windows ... or at least check if bash is available
@@ -468,17 +468,19 @@ elseif(NOT WIN32)
         DESTINATION "etc/sysctl.d"
         )
 
-    #Install vcpkg dynamic libraries in locations defined by GNUInstallDirs.
-    if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-        SET(vcpkg_lib_folder "${VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug/lib/")
-    else()
-        SET(vcpkg_lib_folder "${VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/lib/")
-    endif()
-    install(DIRECTORY "${vcpkg_lib_folder}"
+    if(VCPKG_ROOT)
+        #Install vcpkg dynamic libraries in locations defined by GNUInstallDirs.
+        if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+            SET(vcpkg_lib_folder "${VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug/lib/")
+        else()
+            SET(vcpkg_lib_folder "${VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/lib/")
+        endif()
+        install(DIRECTORY "${vcpkg_lib_folder}"
             DESTINATION ${CMAKE_INSTALL_LIBDIR}
             FILES_MATCHING
             PATTERN "lib*.so*"
             PATTERN "*dylib*" #macOS
             PATTERN "manual-link" EXCLUDE
             PATTERN "pkgconfig" EXCLUDE)
+    endif()
 endif() #not WIN32