diff --git a/dist-build/msys.sh b/dist-build/msys.sh
index 22ca8cb6..b91f2d93 100755
--- a/dist-build/msys.sh
+++ b/dist-build/msys.sh
@@ -1,4 +1,9 @@
 #! /bin/sh
 
 export CFLAGS="-O3 -fomit-frame-pointer -march=pentium2 -mtune=nocona"
-./configure && make && make check && make install
+export PREFIX="$(pwd)/libsodium-win32"
+
+./configure --prefix="$PREFIX" --exec-prefix="$PREFIX" && \
+make && \
+make check && \
+make install