diff --git a/posix/except.cpp b/posix/except.cpp
index ef416417..a45694b1 100644
--- a/posix/except.cpp
+++ b/posix/except.cpp
@@ -29,7 +29,6 @@ using util::posix::error;
 ///
 /// The error value MUST be an error at construction time.
 error::error (int _code):
-    std::runtime_error (::strerror (_code)),
     m_code (_code)
 {
     CHECK_NEQ (_code, 0);
diff --git a/posix/except.hpp b/posix/except.hpp
index 44380baf..f3b03db6 100644
--- a/posix/except.hpp
+++ b/posix/except.hpp
@@ -25,7 +25,7 @@ namespace util::posix {
     ///
     /// Ideally this would be named `errno' but that symbol is permitted to
     /// be a macro and significantly complicates symbol resolution either way.
-    class error : public std::runtime_error {
+    class error : public std::exception {
     public:
         explicit error (int code);
         error ();
@@ -52,6 +52,15 @@ namespace util::posix {
     };
 
 
+    template <int CodeV>
+    struct error_code : public error {
+        error_code ():
+            error (CodeV)
+        { ; }
+    };
+
+
+
     class eai : public std::runtime_error {
     public:
         explicit eai (int code);