diff --git a/MD_Init.c b/MD_Init.c
index d0dada4..a1fa100 100644
--- a/MD_Init.c
+++ b/MD_Init.c
@@ -183,12 +183,12 @@ void md_exit(int exitcode) {
     exit(exitcode);
 }
 
-int md_init(const char *dropfile, int socket) {
+void md_init(const char *dropfile, int socket) {
     char *filename = strrchr(dropfile, PATH_SEP);
 #if !defined(WIN32) && !defined(_MSC_VER)
     struct termios ttystate;
 #endif
-    int ret;
+    int ret = -1;
 
     mdcontrol.socket = socket;
 
@@ -202,6 +202,14 @@ int md_init(const char *dropfile, int socket) {
         ret = read_doorsys(dropfile);
     } else if (strcasecmp(filename, "door32.sys") == 0) {
         ret = read_door32(dropfile);
+    } else {
+        fprintf(stderr, "Unsupported dropfile: %s\n", filename);
+        exit(-1);
+    }
+
+    if (ret == -1) {
+        fprintf(stderr, "Unable to open dropfile: %s\n", dropfile);
+        exit(-1);
     }
 
     if (mdcontrol.socket == -1) {