diff --git a/include/missing.h b/include/missing.h
index c72f40d5e..8cdea34d0 100644
--- a/include/missing.h
+++ b/include/missing.h
@@ -99,6 +99,17 @@
 # endif
 #endif
 
+/*
+ * Pre-C99 compilers may lack a va_copy macro.
+ */
+#ifndef va_copy
+# ifdef __va_copy
+#  define va_copy(d, s) __va_copy(d, s)
+# else
+#  define va_copy(d, s) memcpy(&(d), &(s), sizeof(d));
+# endif
+#endif
+
 /*
  * Some systems lack full limit definitions.
  */
diff --git a/plugins/sudoers/logging.c b/plugins/sudoers/logging.c
index 449eaee37..4cd4398f5 100644
--- a/plugins/sudoers/logging.c
+++ b/plugins/sudoers/logging.c
@@ -59,10 +59,6 @@
 
 #include "sudoers.h"
 
-#ifndef va_copy
-# define va_copy(d, s) memcpy(&(d), &(s), sizeof(d));
-#endif
-
 /* Special message for log_warning() so we know to use ngettext() */
 #define INCORRECT_PASSWORD_ATTEMPT	((char *)0x01)