diff --git a/win32/build/libs_version.txt b/win32/build/libs_version.txt
index 39281d7387f..0d1af3d1b4f 100644
--- a/win32/build/libs_version.txt
+++ b/win32/build/libs_version.txt
@@ -6,7 +6,7 @@ jpeglib-6b
 libcurl-7.24.0
 libiconv-1.11
 libmcrypt-2.5.8
-libmpir-1.3.1
+libmpir-2.5.1
 libpng-1.2.46
 libpq-8.3.6
 libssh2-1.3.0