diff --git a/src/buildno.h b/src/buildno.h
index b04d7a51f..ddec7caa5 100644
--- a/src/buildno.h
+++ b/src/buildno.h
@@ -1,3 +1,3 @@
 #define VERSION_MAJOR 3
 #define VERSION_MINOR 4
-#define VERSION_BUILD 689
+#define VERSION_BUILD 691
diff --git a/src/economy.c b/src/economy.c
index 02c609a73..692a8dfdf 100644
--- a/src/economy.c
+++ b/src/economy.c
@@ -1488,11 +1488,11 @@ static void create_item(unit * u, const item_type * itype, int want)
 int make_cmd(unit * u, struct order *ord)
 {
     region *r = u->region;
-    const building_type *btype;
-    const ship_type *stype;
-    param_t p;
-    int m;
-    const item_type *itype;
+    const building_type *btype = 0;
+    const ship_type *stype = 0;
+    const item_type *itype = 0;
+    param_t p = NOPARAM;
+    int m = INT_MAX;
     const char *s;
     const struct locale *lang = u->faction->locale;
     char ibuf[16];
@@ -1502,17 +1502,19 @@ int make_cmd(unit * u, struct order *ord)
     assert(kwd == K_MAKE);
     s = getstrtoken();
 
-    m = atoi((const char *)s);
-    sprintf(ibuf, "%d", m);
-    if (!strcmp(ibuf, (const char *)s)) {
-        /* first came a want-paramter */
-        s = getstrtoken();
+    if (s) {
+        m = atoi((const char *)s);
+        sprintf(ibuf, "%d", m);
+        if (!strcmp(ibuf, (const char *)s)) {
+            /* a quantity was given */
+            s = getstrtoken();
+        } else {
+            m = INT_MAX;
+        }
+        if (s) {
+            p = findparam(s, u->faction->locale);
+        }
     }
-    else {
-        m = INT_MAX;
-    }
-
-    p = findparam(s, u->faction->locale);
 
     if (p == P_ROAD) {
         plane *pl = rplane(r);
@@ -1551,10 +1553,11 @@ int make_cmd(unit * u, struct order *ord)
      * 'academy of arts', we need to figure out what the player meant.
      * This is not 100% safe.
      */
-    stype = findshiptype(s, lang);
-    btype = findbuildingtype(s, lang);
-    itype = finditemtype(s, lang);
-
+    if (s) {
+        stype = findshiptype(s, lang);
+        btype = findbuildingtype(s, lang);
+        itype = finditemtype(s, lang);
+    }
     if (itype != NULL && (btype != NULL || stype != NULL)) {
         if (itype->construction == NULL) {
             /* if the item cannot be made, we probably didn't mean to make it */
diff --git a/src/magic.c b/src/magic.c
index 5a4cc6404..f31d6afb5 100644
--- a/src/magic.c
+++ b/src/magic.c
@@ -2580,7 +2580,7 @@ static castorder *cast_cmd(unit * u, order * ord)
         }
         s = getstrtoken();
     }
-    if (!s[0] || strlen(s) == 0) {
+    if (!s || !s[0] || strlen(s) == 0) {
         /* Fehler "Es wurde kein Zauber angegeben" */
         cmistake(u, ord, 172, MSG_MAGIC);
         return 0;
diff --git a/src/move.c b/src/move.c
index c4b6b4202..b7fa6feb4 100644
--- a/src/move.c
+++ b/src/move.c
@@ -914,6 +914,8 @@ static unit *bewegung_blockiert_von(unit * reisender, region * r)
             int sk = eff_skill(u, SK_PERCEPTION, r);
             if (invisible(reisender, u) >= reisender->number)
                 continue;
+            if (!(u_race(u)->flags & RCF_FLY) && u_race(reisender)->flags & RCF_FLY)
+                continue;
             if ((u->faction == reisender->faction) || (ucontact(u, reisender)) || (alliedunit(u, reisender->faction, HELP_GUARD)))
                 guard_count = guard_count - u->number;
             else if (sk >= stealth) {
@@ -963,6 +965,8 @@ static bool is_guardian_u(const unit * guard, unit * u, unsigned int mask)
         return false;
     if (!cansee(guard->faction, u->region, u, 0))
         return false;
+    if (!(u_race(guard)->flags & RCF_FLY) && u_race(u)->flags & RCF_FLY)
+        return false;
 
     return true;
 }