diff --git a/FindPreprocThirdparty.cmake b/FindPreprocThirdparty.cmake
index 821a7b0..f8e3640 100644
--- a/FindPreprocThirdparty.cmake
+++ b/FindPreprocThirdparty.cmake
@@ -4,11 +4,13 @@ include(ExternalProject)
 if(PreprocThirdparty_FIND_COMPONENTS STREQUAL "headers")
   ExternalProject_Add(
     libpreproc
+    DEPENDS libpreprocmath
     SOURCE_DIR ${CMAKE_SOURCE_DIR}/thirdparty/libpreproc
     INSTALL_DIR ${CMAKE_BINARY_DIR}
     DOWNLOAD_COMMAND ""
     CONFIGURE_COMMAND
       ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"
+      -DLIBPREPROCMATH_PREFIX=${CMAKE_BINARY_DIR}
       -DCMLIB_MAIN_DIR=${CMLIB_MAIN_DIR} ${CMLIB_EXT_PROJ_DEFAULT_ARGS}
       <SOURCE_DIR>
     BUILD_COMMAND true
@@ -16,15 +18,19 @@ if(PreprocThirdparty_FIND_COMPONENTS STREQUAL "headers")
 else()
   ExternalProject_Add(
     libpreproc
+    DEPENDS libpreprocmath
     SOURCE_DIR ${CMAKE_SOURCE_DIR}/thirdparty/libpreproc
     INSTALL_DIR ${CMAKE_BINARY_DIR}
     DOWNLOAD_COMMAND ""
     CONFIGURE_COMMAND
       ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"
+      -DLIBPREPROCMATH_PREFIX=${CMAKE_BINARY_DIR}
       -DCMLIB_MAIN_DIR=${CMLIB_MAIN_DIR} ${CMLIB_EXT_PROJ_DEFAULT_ARGS}
       <SOURCE_DIR>)
 endif()
 
+set(LIBPREPROC_IS_EXTERNAL_PROJECT ON CACHE BOOL "" FORCE)
+
 set(LIBPREPROC_PREFIX
     ${CMAKE_BINARY_DIR}
     CACHE FILEPATH "" FORCE)
diff --git a/FindPreprocmathThirdparty.cmake b/FindPreprocmathThirdparty.cmake
index 080706c..67c67ce 100644
--- a/FindPreprocmathThirdparty.cmake
+++ b/FindPreprocmathThirdparty.cmake
@@ -1,7 +1,7 @@
 # Подключение внешних проектов
 include(ExternalProject)
 
-if(${PreprocmathThirdparty_FIND_COMPONENTS} STREQUAL "headers")
+if(PreprocmathThirdparty_FIND_COMPONENTS STREQUAL "headers")
   ExternalProject_Add(
     libpreprocmath
     SOURCE_DIR ${CMAKE_SOURCE_DIR}/thirdparty/libpreprocmath
@@ -25,6 +25,8 @@ else()
       <SOURCE_DIR>)
 endif()
 
+set(LIBPREPROCMATH_IS_EXTERNAL_PROJECT ON CACHE BOOL "" FORCE)
+
 set(LIBPREPROCMATH_PREFIX
     ${CMAKE_BINARY_DIR}
     CACHE FILEPATH "" FORCE)