diff --git a/src/input/Error.cxx b/src/input/Error.cxx
index 3db1f26f1..b3f0e7e65 100644
--- a/src/input/Error.cxx
+++ b/src/input/Error.cxx
@@ -31,7 +31,7 @@
 #endif
 
 bool
-IsFileNotFound(std::exception_ptr ep)
+IsFileNotFound(std::exception_ptr ep) noexcept
 {
 	try {
 		std::rethrow_exception(ep);
diff --git a/src/input/Error.hxx b/src/input/Error.hxx
index c857f827e..04ea27ab8 100644
--- a/src/input/Error.hxx
+++ b/src/input/Error.hxx
@@ -32,6 +32,6 @@
  */
 gcc_pure
 bool
-IsFileNotFound(std::exception_ptr e);
+IsFileNotFound(std::exception_ptr e) noexcept;
 
 #endif