diff --git a/lib/std/special/compiler_rt/divtf3_test.zig b/lib/std/special/compiler_rt/divtf3_test.zig
index 925f8bbc91..62204057d4 100644
--- a/lib/std/special/compiler_rt/divtf3_test.zig
+++ b/lib/std/special/compiler_rt/divtf3_test.zig
@@ -34,8 +34,12 @@ test "divtf3" {
     try test__divtf3(math.qnan_f128, 0x1.23456789abcdefp+5, 0x7fff800000000000, 0);
     // NaN / any = NaN
     try test__divtf3(math.nan_f128, 0x1.23456789abcdefp+5, 0x7fff800000000000, 0);
-    // inf / any = inf
+    // inf / any(except inf and nan) = inf
     try test__divtf3(math.inf(f128), 0x1.23456789abcdefp+5, 0x7fff000000000000, 0);
+    // inf / inf = nan
+    try test__divtf3(math.inf(f128), math.inf(f128), 0x7fff800000000000, 0);
+    // inf / nan = nan
+    try test__divtf3(math.inf(f128), math.nan(f128), 0x7fff800000000000, 0);
 
     try test__divtf3(0x1.a23b45362464523375893ab4cdefp+5, 0x1.eedcbaba3a94546558237654321fp-1, 0x4004b0b72924d407, 0x0717e84356c6eba2);
     try test__divtf3(0x1.a2b34c56d745382f9abf2c3dfeffp-50, 0x1.ed2c3ba15935332532287654321fp-9, 0x3fd5b2af3f828c9b, 0x40e51f64cde8b1f2);