--- ../pigz-2.1.5/pigz.c	2009-07-20 04:42:00.000000000 +0200
+++ pigz.c	2009-11-24 10:50:13.000000000 +0100
@@ -3075,9 +3075,17 @@
     if (argc < 2 && isatty(1))
         help();
 
-    /* decompress if named "unpigz" */
+    /* find program name */
     p = strrchr(argv[0], '/');
-    if (strcmp(p == NULL ? argv[0] : p + 1, "unpigz") == 0)
+    if (p == NULL) {
+        p = argv[0];
+    }
+    else {
+        ++p;
+    }    
+
+    /* decompress if named "unpigz" or "gunzip" */
+    if ((strcmp(p, "unpigz") == 0) || (strcmp(p, "gunzip") == 0))
         decode = 1, headis = 0;
 
     /* process command-line arguments */