diff --git a/deps/CMakeLists.txt b/deps/CMakeLists.txt
index 3935e38c3..1a98afad8 100644
--- a/deps/CMakeLists.txt
+++ b/deps/CMakeLists.txt
@@ -49,6 +49,10 @@ find_package(Git REQUIRED)
 
 get_property(_is_multi GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
 
+# C and CXX flags handed over to unix autotools projects.
+set(DEP_CFLAGS "")
+set(DEP_CXXFLAGS "")
+
 function(prusaslicer_add_cmake_project projectname)
     cmake_parse_arguments(P_ARGS "" "INSTALL_DIR;BUILD_COMMAND;INSTALL_COMMAND" "CMAKE_ARGS" ${ARGN})
 
diff --git a/deps/GMP/GMP.cmake b/deps/GMP/GMP.cmake
index 4e8228cba..aa23a24e9 100644
--- a/deps/GMP/GMP.cmake
+++ b/deps/GMP/GMP.cmake
@@ -21,8 +21,8 @@ else ()
         # URL  https://gmplib.org/download/gmp/gmp-6.1.2.tar.bz2
         URL https://gmplib.org/download/gmp/gmp-6.2.0.tar.lz
         BUILD_IN_SOURCE ON 
-        CONFIGURE_COMMAND ./configure --enable-shared=no --enable-cxx=yes --enable-static=yes "--prefix=${DESTDIR}/usr/local" --with-pic
+        CONFIGURE_COMMAND env "CFLAGS=${DEP_CFLAGS}" "CXXFLAGS=${DEP_CXXFLAGS}" ./configure --enable-shared=no --enable-cxx=yes --enable-static=yes "--prefix=${DESTDIR}/usr/local" --with-pic
         BUILD_COMMAND     make -j
         INSTALL_COMMAND   make install
-    )
+    ) 
 endif ()
\ No newline at end of file
diff --git a/deps/MPFR/MPFR.cmake b/deps/MPFR/MPFR.cmake
index cda7eeea9..89073fb73 100644
--- a/deps/MPFR/MPFR.cmake
+++ b/deps/MPFR/MPFR.cmake
@@ -21,7 +21,7 @@ else ()
     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 ./configure --prefix=${DESTDIR}/usr/local --enable-shared=no --enable-static=yes --with-gmp=${DESTDIR}/usr/local --with-pic
+        CONFIGURE_COMMAND env "CFLAGS=${DEP_CFLAGS}" "CXXFLAGS=${DEP_CXXFLAGS}" ./configure --prefix=${DESTDIR}/usr/local --enable-shared=no --enable-static=yes --with-gmp=${DESTDIR}/usr/local --with-pic
         BUILD_COMMAND make -j
         INSTALL_COMMAND make install
         DEPENDS dep_GMP
diff --git a/deps/deps-macos.cmake b/deps/deps-macos.cmake
index 17300b247..fbf2d6c48 100644
--- a/deps/deps-macos.cmake
+++ b/deps/deps-macos.cmake
@@ -11,6 +11,9 @@ set(DEP_CMAKE_OPTS
     "-DCMAKE_C_FLAGS=${DEP_WERRORS_SDK}"
 )
 
+list(APPEND DEP_CFLAGS "-mmacosx-version-min=${DEP_OSX_TARGET} ${DEP_WERRORS_SDK}")
+list(APPEND DEP_CXXFLAGS "-mmacosx-version-min=${DEP_OSX_TARGET} ${DEP_WERRORS_SDK}")
+
 include("deps-unix-common.cmake")