diff -p -up yacas-1.2.2/src/stdcommandline.cpp.strfmt yacas-1.2.2/src/stdcommandline.cpp
--- yacas-1.2.2/src/stdcommandline.cpp.strfmt	2009-05-24 23:05:47.000000000 +0200
+++ yacas-1.2.2/src/stdcommandline.cpp	2009-05-24 23:06:16.000000000 +0200
@@ -33,7 +33,7 @@ LispInt CStdCommandLine::GetKey()
 
 void CStdCommandLine::ReadLine(LispChar * prompt)
 {
-    printf(prompt); fflush(stdout);
+    printf("%s", prompt); fflush(stdout);
     char buffer[4001];
     int offs=0;
 MORE: