diff --git a/core/gmp/build b/core/gmp/build
index 5ad8abf3..9766e0ad 100755
--- a/core/gmp/build
+++ b/core/gmp/build
@@ -3,6 +3,8 @@
 cp -v configfsf.guess config.guess
 cp -v configfsf.sub   config.sub
 
+unset CFLAGS CXXFLAGS
+
 ./configure \
     --prefix=/usr \
     --localstatedir=/var/state/gmp \