diff --git a/Misc/NEWS.d/next/Library/2024-09-17-18-06-42.gh-issue-124171.PHCvRJ.rst b/Misc/NEWS.d/next/Library/2024-09-17-18-06-42.gh-issue-124171.PHCvRJ.rst
new file mode 100644
index 00000000000000..c2f0bb14f55251
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-09-17-18-06-42.gh-issue-124171.PHCvRJ.rst
@@ -0,0 +1,3 @@
+Add workaround for broken :c:func:`!fmod()` implementations on Windows, that
+loose zero sign (e.g. ``fmod(-10, 1)`` returns ``0.0``).  Patch by Sergey B
+Kirpichev.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 000803981edcf4..d856ff6c354a40 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -2343,6 +2343,15 @@ math_fmod_impl(PyObject *module, double x, double y)
         return PyFloat_FromDouble(x);
     errno = 0;
     r = fmod(x, y);
+#ifdef _MSC_VER
+    /* Windows (e.g. Windows 10 with MSC v.1916) loose sign
+       for zero result.  But C99+ says: "if y is nonzero, the result
+       has the same sign as x".
+     */
+    if (r == 0.0 && y != 0.0) {
+        r = copysign(r, x);
+    }
+#endif
     if (Py_IS_NAN(r)) {
         if (!Py_IS_NAN(x) && !Py_IS_NAN(y))
             errno = EDOM;