diff --git a/libstdc++-v3/src/c++11/system_error.cc b/libstdc++-v3/src/c++11/system_error.cc
index f12290adaeea..6c79202eb0ee 100644
--- a/libstdc++-v3/src/c++11/system_error.cc
+++ b/libstdc++-v3/src/c++11/system_error.cc
@@ -70,6 +70,8 @@ namespace
     virtual std::error_condition
     default_error_condition(int ev) const noexcept
     {
+      // Use generic category for all known POSIX errno values (including zero)
+      // and system category otherwise.
       switch (ev)
       {
       // List of errno macros from [cerrno.syn].
@@ -310,6 +312,7 @@ namespace
 #ifdef EXDEV
       case EXDEV:
 #endif
+      case 0:
         return std::error_condition(ev, std::generic_category());
 
       /* Additional system-dependent mappings from non-standard error codes
diff --git a/libstdc++-v3/testsuite/19_diagnostics/error_category/102425.cc b/libstdc++-v3/testsuite/19_diagnostics/error_category/102425.cc
new file mode 100644
index 000000000000..069b5e284e1c
--- /dev/null
+++ b/libstdc++-v3/testsuite/19_diagnostics/error_category/102425.cc
@@ -0,0 +1,18 @@
+// { dg-do run { target c++11 } }
+#include <system_error>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  // PR libstdc++/102425
+  VERIFY( std::error_code() == std::error_condition() );
+
+  auto zero = std::system_category().default_error_condition(0);
+  // This is the condition that the equality above relies on:
+  VERIFY( zero.category() == std::generic_category() );
+}
+
+int main()
+{
+  test01();
+}