diff --git a/fileio.c b/fileio.c
index a001dd4..4eb7e29 100644
--- a/fileio.c
+++ b/fileio.c
@@ -1580,7 +1580,8 @@ int UZ_EXP UzpPassword (pG, rcnt, pwbuf, size, zfn, efn)
     int r = IZ_PW_ENTERED;
     char *m;
     char *prompt;
-
+    char *ep;
+    char *zp;
 #ifndef REENTRANT
     /* tell picky compilers to shut up about "unused variable" warnings */
     pG = pG;
@@ -1588,9 +1589,12 @@ int UZ_EXP UzpPassword (pG, rcnt, pwbuf, size, zfn, efn)
 
     if (*rcnt == 0) {           /* First call for current entry */
         *rcnt = 2;
-        if ((prompt = (char *)malloc(2*FILNAMSIZ + 15)) != (char *)NULL) {
-            sprintf(prompt, LoadFarString(PasswPrompt),
-                    FnFilter1(zfn), FnFilter2(efn));
+        zp = FnFilter1( zfn);
+        ep = FnFilter2( efn);
+        prompt = (char *)malloc(    /* Slightly too long (2* "%s"). */
+         sizeof( PasswPrompt)+ strlen( zp)+ strlen( ep));
+        if (prompt != (char *)NULL) {
+            sprintf(prompt, LoadFarString(PasswPrompt), zp, ep);
             m = prompt;
         } else
             m = (char *)LoadFarString(PasswPrompt2);