diff --git a/libmaxsi/decl/errno_values.h b/libmaxsi/decl/errno_values.h
index 783051be..2ed85153 100644
--- a/libmaxsi/decl/errno_values.h
+++ b/libmaxsi/decl/errno_values.h
@@ -23,5 +23,6 @@
 #define ENOTTY 31
 #define ECHILD 32
 #define ENOSYS 33
+#define ENOTSUP 34
 
 #endif
diff --git a/libmaxsi/error.cpp b/libmaxsi/error.cpp
index 9ebede16..d74d2b0d 100644
--- a/libmaxsi/error.cpp
+++ b/libmaxsi/error.cpp
@@ -71,6 +71,7 @@ namespace Maxsi
 				case ENOTTY: return (char*) "Not a tty";
 				case ECHILD: return (char*) "No child processes";
 				case ENOSYS: return (char*) "Function not implemented";
+				case ENOTSUP: return (char*) "Operation not supported";
 				default: return (char*) "Unknown error condition";
 			}
 		}