diff --git a/libmaxsi/decl/errno_values.h b/libmaxsi/decl/errno_values.h
index cee3bf07..8ade04e0 100644
--- a/libmaxsi/decl/errno_values.h
+++ b/libmaxsi/decl/errno_values.h
@@ -29,6 +29,7 @@
 #define ENOTEMPTY 37
 #define EBUSY 38
 #define EPIPE 39
+#define EILSEQ 40
 #define ELAKE 41
 
 #endif
diff --git a/libmaxsi/error.cpp b/libmaxsi/error.cpp
index 1e1338bf..9021f97b 100644
--- a/libmaxsi/error.cpp
+++ b/libmaxsi/error.cpp
@@ -77,6 +77,7 @@ namespace Maxsi
 				case ENOTEMPTY: return (char*) "Directory not empty";
 				case EBUSY: return (char*) "Device or resource busy";
 				case EPIPE: return (char*) "Broken pipe";
+				case EILSEQ: return (char*) "Illegal byte sequence";
 				case ELAKE: return (char*) "Sit by a lake";
 				default: return (char*) "Unknown error condition";
 			}