diff -Naur sane-backends-1.0.24.orig/frontend/scanimage.c sane-backends-1.0.24/frontend/scanimage.c
--- sane-backends-1.0.24.orig/frontend/scanimage.c	2013-08-25 23:22:58.000000000 +0200
+++ sane-backends-1.0.24/frontend/scanimage.c	2014-04-14 21:04:13.512000000 +0200
@@ -1894,7 +1894,7 @@
 				printf (start, int_arg);
 				break;
 			      case 0:
-				printf (start);
+				printf ("%s", start);
 				break;
 			      }
 			    *percent = cc;
@@ -1908,7 +1908,7 @@
 			  }
 		      }
 		    if (*start)
-		      printf (start);
+		      printf ("%s", start);
 		  }
 	      }
 	    if (i == 0 && ch != 'f')