diff --git a/configure/os/CONFIG.win32-x86-mingw.win32-x86-mingw b/configure/os/CONFIG.win32-x86-mingw.win32-x86-mingw
index 02c569042..f64992142 100644
--- a/configure/os/CONFIG.win32-x86-mingw.win32-x86-mingw
+++ b/configure/os/CONFIG.win32-x86-mingw.win32-x86-mingw
@@ -32,5 +32,8 @@ CONFORM_CXXFLAGS_STRICT =
 # Override linking with gcc library from CONFIG.gnuCommon
 GNU_LDLIBS_YES =
 
+OPT_CFLAGS_NO = -O3 -g
+OPT_CXXFLAGS_NO = -O3 -g
+
 OP_SYS_LDLIBS = -lws2_32 
 PROD_SYS_LIBS = ws2_32