diff --git a/include/boost/math/special_functions/acosh.hpp b/include/boost/math/special_functions/acosh.hpp
index cdc4905599..9db69ec91a 100644
--- a/include/boost/math/special_functions/acosh.hpp
+++ b/include/boost/math/special_functions/acosh.hpp
@@ -22,6 +22,7 @@
 #include <boost/math/special_functions/math_fwd.hpp>
 #include <boost/math/special_functions/log1p.hpp>
 #include <boost/math/constants/constants.hpp>
+#include <boost/math/special_functions/fpclassify.hpp>
 
 // This is the inverse of the hyperbolic cosine function.
 
diff --git a/include/boost/math/special_functions/asinh.hpp b/include/boost/math/special_functions/asinh.hpp
index e55a356284..3dc1f63f48 100644
--- a/include/boost/math/special_functions/asinh.hpp
+++ b/include/boost/math/special_functions/asinh.hpp
@@ -23,6 +23,7 @@
 #include <boost/math/special_functions/sqrt1pm1.hpp>
 #include <boost/math/special_functions/log1p.hpp>
 #include <boost/math/constants/constants.hpp>
+#include <boost/math/special_functions/fpclassify.hpp>
 
 // This is the inverse of the hyperbolic sine function.
 
diff --git a/include/boost/math/special_functions/atanh.hpp b/include/boost/math/special_functions/atanh.hpp
index 871a465a8c..c2d548dd32 100644
--- a/include/boost/math/special_functions/atanh.hpp
+++ b/include/boost/math/special_functions/atanh.hpp
@@ -22,6 +22,7 @@
 #include <boost/math/policies/error_handling.hpp>
 #include <boost/math/special_functions/math_fwd.hpp>
 #include <boost/math/special_functions/log1p.hpp>
+#include <boost/math/special_functions/fpclassify.hpp>
 
 // This is the inverse of the hyperbolic tangent function.
 
diff --git a/include/boost/math/special_functions/log1p.hpp b/include/boost/math/special_functions/log1p.hpp
index 7126cc8193..44b1844e70 100644
--- a/include/boost/math/special_functions/log1p.hpp
+++ b/include/boost/math/special_functions/log1p.hpp
@@ -21,6 +21,7 @@
 #include <boost/math/tools/big_constant.hpp>
 #include <boost/math/policies/error_handling.hpp>
 #include <boost/math/special_functions/math_fwd.hpp>
+#include <boost/math/special_functions/fpclassify.hpp>
 
 #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
 #  include <boost/static_assert.hpp>