diff --git a/libastro/constel.c b/libastro/constel.c
index 221b3a2..9ccf5aa 100644
--- a/libastro/constel.c
+++ b/libastro/constel.c
@@ -1673,7 +1673,7 @@ cns_loadfigs (FILE *fp, char *msg)
 		continue;
 
 	    /* ok, line looks interesting, look more carefully */
-	    if (sscanf (lp, "%d %s %s", &code, rastr, decstr) == 3) {
+	    if (sscanf (lp, "%d %63s %63s", &code, rastr, decstr) == 3) {
 		/* looks like a drawing line */
 		double ra, dec;
 
diff --git a/libastro/magdecl.c b/libastro/magdecl.c
index c8ff40b..66dc9e5 100644
--- a/libastro/magdecl.c
+++ b/libastro/magdecl.c
@@ -148,7 +148,7 @@ GEOMAG:
       c[0][0] = 0.0;
       cd[0][0] = 0.0;
       fgets(c_str, 80, wmmdat);
-      sscanf(c_str,"%f%s",&epoc,model);
+      sscanf(c_str,"%f%19s",&epoc,model);
 S3:
       fgets(c_str, 80, wmmdat);
 /* CHECK FOR LAST LINE IN FILE */
diff --git a/libastro/misc.c b/libastro/misc.c
index 06a0672..264cc5f 100644
--- a/libastro/misc.c
+++ b/libastro/misc.c
@@ -140,7 +140,7 @@ obj_description (Obj *op)
 		return ("Planet");
 	    if (!biop)
 		getBuiltInObjs (&biop);
-	    sprintf (nsstr, "Moon of %s", biop[op->pl_code].o_name);
+	    sprintf (nsstr, "Moon of %7s", biop[op->pl_code].o_name);
 	    return (nsstr);
 	    }
 	case EARTHSAT: