diff --git a/tests/math_test.cpp b/tests/math_test.cpp
index 4affc22..7ca0e75 100644
--- a/tests/math_test.cpp
+++ b/tests/math_test.cpp
@@ -309,9 +309,7 @@
 // Historical BSD cruft that isn't exposed in <math.h> any more.
 extern "C" int __isinf(double);
 extern "C" int __isinff(float);
-extern "C" int isinff(float);
 extern "C" int __isinfl(long double);
-extern "C" int isinfl(long double);
 
 TEST(math_h, __isinf) {
 #if defined(ANDROID_HOST_MUSL)