diff --git a/include/common/standard.h b/include/common/standard.h
index 7536a64..0900798 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -1224,6 +1224,16 @@
  */
 char *indent_msg(char **out, int level);
 
+/* removes environment variable <name> from the environment as found in
+ * environ. This is only provided as an alternative for systems without
+ * unsetenv() (old Solaris and AIX versions). THIS IS NOT THREAD SAFE.
+ * The principle is to scan environ for each occurence of variable name
+ * <name> and to replace the matching pointers with the last pointer of
+ * the array (since variables are not ordered).
+ * It always returns 0 (success).
+ */
+int my_unsetenv(const char *name);
+
 /* Convert occurrences of environment variables in the input string to their
  * corresponding value. A variable is identified as a series of alphanumeric
  * characters or underscores following a '$' sign. The <in> string must be