diff --git a/quickjs.c b/quickjs.c
index b6a2df5f..5be082ff 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -62,7 +62,7 @@
 #define MALLOC_OVERHEAD  8
 #endif
 
-#if !defined(_WIN32)
+#if !defined(_WIN32) || defined(__MINGW32__)
 /* define it if printf uses the RNDN rounding mode instead of RNDNA */
 #define CONFIG_PRINTF_RNDN
 #endif
diff --git a/tests/test_builtin.js b/tests/test_builtin.js
index 4ce2355c..4e571aa4 100644
--- a/tests/test_builtin.js
+++ b/tests/test_builtin.js
@@ -341,11 +341,6 @@ function test_number()
     assert(Number.isNaN(Number("-")));
     assert(Number.isNaN(Number("\x00a")));
 
-    // TODO: Fix rounding error on MinGW.
-    if (std.getenv('MSYSTEM')) {
-        return;
-    }
-
     assert((25).toExponential(0), "3e+1");
     assert((-25).toExponential(0), "-3e+1");
     assert((2.5).toPrecision(1), "3");