diff --git a/tests/math_test.cpp b/tests/math_test.cpp
index 7734018..6758af1 100644
--- a/tests/math_test.cpp
+++ b/tests/math_test.cpp
@@ -239,6 +239,12 @@
   ASSERT_FALSE(finite(HUGE_VAL));
 }
 
+TEST(math, isinf_function) {
+  // The isinf macro deals with all three types; the isinf function is for doubles.
+  ASSERT_FALSE((isinf)(123.0));
+  ASSERT_TRUE((isinf)(HUGE_VAL));
+}
+
 TEST(math, __isinff) {
   ASSERT_FALSE(__isinff(123.0f));
   ASSERT_TRUE(__isinff(HUGE_VALF));
@@ -249,6 +255,12 @@
   ASSERT_TRUE(__isinfl(HUGE_VALL));
 }
 
+TEST(math, isnan_function) {
+  // The isnan macro deals with all three types; the isnan function is for doubles.
+  ASSERT_FALSE((isnan)(123.0));
+  ASSERT_TRUE((isnan)(nan("")));
+}
+
 TEST(math, __isnanf) {
   ASSERT_FALSE(__isnanf(123.0f));
   ASSERT_TRUE(__isnanf(nanf("")));