diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index fb554ab156..150f6c0582 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -373,6 +373,10 @@ int s390_ipl_set_loadparm(uint8_t *loadparm)
             loadparm[i] = ascii2ebcdic[(uint8_t) lp[i]];
         }
 
+        if (i < 8) {
+            memset(loadparm + i, 0x40, 8 - i); /* fill with EBCDIC spaces */
+        }
+
         g_free(lp);
         return 0;
     }
diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 9d9f8cf4d3..26f9adf84a 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -15,11 +15,11 @@
 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
 static SubChannelId blk_schid = { .one = 1 };
 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
-static char loadparm[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+static char loadparm_str[9] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 QemuIplParameters qipl;
 
 #define LOADPARM_PROMPT "PROMPT  "
-#define LOADPARM_EMPTY  "........"
+#define LOADPARM_EMPTY  "        "
 #define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL)
 
 /*
@@ -45,7 +45,7 @@ void panic(const char *string)
 
 unsigned int get_loadparm_index(void)
 {
-    return atoui(loadparm);
+    return atoui(loadparm_str);
 }
 
 static bool find_dev(Schib *schib, int dev_no)
@@ -80,13 +80,13 @@ static bool find_dev(Schib *schib, int dev_no)
 
 static void menu_setup(void)
 {
-    if (memcmp(loadparm, LOADPARM_PROMPT, 8) == 0) {
+    if (memcmp(loadparm_str, LOADPARM_PROMPT, 8) == 0) {
         menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
         return;
     }
 
     /* If loadparm was set to any other value, then do not enable menu */
-    if (memcmp(loadparm, LOADPARM_EMPTY, 8) != 0) {
+    if (memcmp(loadparm_str, LOADPARM_EMPTY, 8) != 0) {
         return;
     }
 
@@ -116,8 +116,8 @@ static void virtio_setup(void)
      */
     enable_mss_facility();
 
-    sclp_get_loadparm_ascii(loadparm);
-    memcpy(ldp + 10, loadparm, 8);
+    sclp_get_loadparm_ascii(loadparm_str);
+    memcpy(ldp + 10, loadparm_str, 8);
     sclp_print(ldp);
 
     memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));