diff --git a/deps/GMP/GMP.cmake b/deps/GMP/GMP.cmake
index a7fe19355f..4b965ae133 100644
--- a/deps/GMP/GMP.cmake
+++ b/deps/GMP/GMP.cmake
@@ -36,11 +36,17 @@ else ()
         set(_gmp_build_tgt "") # let it guess
     endif()
 
+    set(_cross_compile_arg "")
+    if (CMAKE_CROSSCOMPILING)
+        # TOOLCHAIN_PREFIX should be defined in the toolchain file
+        set(_cross_compile_arg --host=${TOOLCHAIN_PREFIX})
+    endif ()
+
     ExternalProject_Add(dep_GMP
         # URL  https://gmplib.org/download/gmp/gmp-6.1.2.tar.bz2
         URL https://gmplib.org/download/gmp/gmp-6.2.1.tar.bz2
         BUILD_IN_SOURCE ON 
-        CONFIGURE_COMMAND  env "CFLAGS=${_gmp_ccflags}" "CXXFLAGS=${_gmp_ccflags}" ./configure --enable-shared=no --enable-cxx=yes --enable-static=yes "--prefix=${DESTDIR}/usr/local" ${_gmp_build_tgt}
+        CONFIGURE_COMMAND  env "CFLAGS=${_gmp_ccflags}" "CXXFLAGS=${_gmp_ccflags}" ./configure ${_cross_compile_arg} --enable-shared=no --enable-cxx=yes --enable-static=yes "--prefix=${DESTDIR}/usr/local" ${_gmp_build_tgt}
         BUILD_COMMAND     make -j
         INSTALL_COMMAND   make install
     )
diff --git a/deps/MPFR/MPFR.cmake b/deps/MPFR/MPFR.cmake
index ddbb178d8d..a4e30e645c 100644
--- a/deps/MPFR/MPFR.cmake
+++ b/deps/MPFR/MPFR.cmake
@@ -18,10 +18,17 @@ if (MSVC)
     add_custom_target(dep_MPFR SOURCES ${_output})
 
 else ()
+
+    set(_cross_compile_arg "")
+    if (CMAKE_CROSSCOMPILING)
+        # TOOLCHAIN_PREFIX should be defined in the toolchain file
+        set(_cross_compile_arg --host=${TOOLCHAIN_PREFIX})
+    endif ()
+
     ExternalProject_Add(dep_MPFR
         URL http://ftp.vim.org/ftp/gnu/mpfr/mpfr-3.1.6.tar.bz2 https://www.mpfr.org/mpfr-3.1.6/mpfr-3.1.6.tar.bz2  # mirrors are allowed
         BUILD_IN_SOURCE ON
-        CONFIGURE_COMMAND env "CFLAGS=${_gmp_ccflags}" "CXXFLAGS=${_gmp_ccflags}" ./configure --prefix=${DESTDIR}/usr/local --enable-shared=no --enable-static=yes --with-gmp=${DESTDIR}/usr/local ${_gmp_build_tgt}
+        CONFIGURE_COMMAND env "CFLAGS=${_gmp_ccflags}" "CXXFLAGS=${_gmp_ccflags}" ./configure ${_cross_compile_arg} --prefix=${DESTDIR}/usr/local --enable-shared=no --enable-static=yes --with-gmp=${DESTDIR}/usr/local ${_gmp_build_tgt}
         BUILD_COMMAND make -j
         INSTALL_COMMAND make install
         DEPENDS dep_GMP