diff --git a/src/Sema.zig b/src/Sema.zig
index a3dccf1d7d..7666b2c9ec 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -15816,6 +15816,13 @@ fn cmpNumeric(
                 if (lhs_val.isUndef() or rhs_val.isUndef()) {
                     return sema.addConstUndef(Type.bool);
                 }
+                if (lhs_val.isNan() or rhs_val.isNan()) {
+                    if (op == std.math.CompareOperator.neq) {
+                        return Air.Inst.Ref.bool_true;
+                    } else {
+                        return Air.Inst.Ref.bool_false;
+                    }
+                }
                 if (Value.compareHetero(lhs_val, op, rhs_val)) {
                     return Air.Inst.Ref.bool_true;
                 } else {
diff --git a/test/behavior/math.zig b/test/behavior/math.zig
index 77820ac0fb..8f947e2829 100644
--- a/test/behavior/math.zig
+++ b/test/behavior/math.zig
@@ -979,18 +979,16 @@ test "vector integer addition" {
 }
 
 test "NaN comparison" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
-
     try testNanEqNan(f16);
     try testNanEqNan(f32);
     try testNanEqNan(f64);
     try testNanEqNan(f128);
-    if (has_f80_rt) try testNanEqNan(f80);
+    if (has_f80_rt and (builtin.zig_backend == .stage1)) try testNanEqNan(f80); // TODO
     comptime try testNanEqNan(f16);
     comptime try testNanEqNan(f32);
     comptime try testNanEqNan(f64);
     comptime try testNanEqNan(f128);
-    // comptime try testNanEqNan(f80);
+    // comptime try testNanEqNan(f80); // TODO
 }
 
 fn testNanEqNan(comptime F: type) !void {