diff --git a/modules/highgui/cmake/init.cmake b/modules/highgui/cmake/init.cmake
index a302c4d534..2002ff0e9d 100644
--- a/modules/highgui/cmake/init.cmake
+++ b/modules/highgui/cmake/init.cmake
@@ -25,7 +25,9 @@ endif()
 # Detect available dependencies
 #
 
-include(FindPkgConfig)
+if(NOT PROJECT_NAME STREQUAL "OpenCV")
+  include(FindPkgConfig)
+endif()
 
 macro(add_backend backend_id cond_var)
   if(${cond_var})
diff --git a/modules/videoio/cmake/init.cmake b/modules/videoio/cmake/init.cmake
index 68838790b8..af664f94df 100644
--- a/modules/videoio/cmake/init.cmake
+++ b/modules/videoio/cmake/init.cmake
@@ -1,4 +1,6 @@
-include(FindPkgConfig)
+if(NOT PROJECT_NAME STREQUAL "OpenCV")
+  include(FindPkgConfig)
+endif()
 
 macro(add_backend backend_id cond_var)
   if(${cond_var})
diff --git a/platforms/linux/gnu.toolchain.cmake b/platforms/linux/gnu.toolchain.cmake
index cba08e7fbb..64258e65b3 100644
--- a/platforms/linux/gnu.toolchain.cmake
+++ b/platforms/linux/gnu.toolchain.cmake
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.5)
 
 # load settings in case of "try compile"
 set(TOOLCHAIN_CONFIG_FILE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/toolchain.config.cmake")
diff --git a/platforms/linux/riscv.toolchain.cmake b/platforms/linux/riscv.toolchain.cmake
index 2a69d7e004..cea80bd9ba 100644
--- a/platforms/linux/riscv.toolchain.cmake
+++ b/platforms/linux/riscv.toolchain.cmake
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.5)
 
 if(COMMAND toolchain_save_config)
   return() # prevent recursive call