diff --git a/lib/wsprd/wsprd.c b/lib/wsprd/wsprd.c
index 522b7097f..8ef66fd19 100644
--- a/lib/wsprd/wsprd.c
+++ b/lib/wsprd/wsprd.c
@@ -875,10 +875,12 @@ int main(int argc, char *argv[])
         }
     }
     
-    if( stackdecoder ) {
-        stack=calloc(stacksize,sizeof(struct snode));
+    if( access(data_dir, R_OK | W_OK)) {
+      fprintf(stderr, "Error: inaccessible data directory: '%s'\n", data_dir);
+      usage();
+      return EXIT_FAILURE;
     }
-    
+
     if( optind+1 > argc) {
         usage();
         return 1;
@@ -886,6 +888,10 @@ int main(int argc, char *argv[])
         ptr_to_infile=argv[optind];
     }
     
+    if( stackdecoder ) {
+        stack=calloc(stacksize,sizeof(struct snode));
+    }
+
     // setup metric table
     for(i=0; i<256; i++) {
         mettab[0][i]=round( 10*(metric_tables[2][i]-bias) );