diff --git a/libc/decl/errno_values.h b/libc/decl/errno_values.h
index 89a8ab1c..99a08634 100644
--- a/libc/decl/errno_values.h
+++ b/libc/decl/errno_values.h
@@ -62,6 +62,7 @@
 #define EFAULT 70
 #define EDESTADDRREQ 71
 #define EHOSTUNREACH 72
+#define EMSGSIZE 73
 
 #define EOPNOTSUPP ENOTSUP
 
diff --git a/libc/strerror.cpp b/libc/strerror.cpp
index 28fa6fbb..383d0e07 100644
--- a/libc/strerror.cpp
+++ b/libc/strerror.cpp
@@ -91,6 +91,7 @@ extern "C" const char* sortix_strerror(int errnum)
 	case EFAULT: return "Bad address";
 	case EDESTADDRREQ: return "Destinatiohn address required";
 	case EHOSTUNREACH: return "Host is unreachable";
+	case EMSGSIZE: return "Message too long";
 	default: return "Unknown error condition";
 	}
 }