diff --git a/include/prototypes.h b/include/prototypes.h
index ade09bd0..c717185d 100644
--- a/include/prototypes.h
+++ b/include/prototypes.h
@@ -330,7 +330,7 @@ extern int gamehours(time_t, int *);
 extern int has_units(coord, coord, natid, struct lndstr *);
 extern int has_units_with_mob(coord, coord, natid);
 extern int adj_units(coord, coord, natid);
-extern int is_engineer(int x, int y);
+extern int has_helpful_engineer(coord x, coord y, natid cn);
 /* log.c */
 extern void loginit(void);
 extern void logerror(s_char *, ...);
diff --git a/src/lib/common/land.c b/src/lib/common/land.c
index 627f7e6f..8ebebfd8 100644
--- a/src/lib/common/land.c
+++ b/src/lib/common/land.c
@@ -97,14 +97,19 @@ has_units_with_mob(coord x, coord y, natid cn)
     return 0;
 }
 
+/*
+ * Is there a engineer unit at X,Y that can help nation CN?
+ */
 int
-is_engineer(int x, int y)
+has_helpful_engineer(coord x, coord y, natid cn)
 {
     struct nstr_item ni;
     struct lndstr land;
 
     snxtitem_xy(&ni, EF_LAND, x, y);
     while (nxtitem(&ni, (s_char *)&land)) {
+	if (land.lnd_own != cn && getrel(getnatp(land.lnd_own), cn) != ALLIED)
+	    continue;
 	if (lchr[(int)land.lnd_type].l_flags & L_ENGINEER)
 	    return 1;
     }
diff --git a/src/lib/subs/lndsub.c b/src/lib/subs/lndsub.c
index 80f9230a..8799864c 100644
--- a/src/lib/subs/lndsub.c
+++ b/src/lib/subs/lndsub.c
@@ -1367,7 +1367,7 @@ lnd_fortify (struct lndstr *lp, int hard_amt)
     if ((lp->lnd_harden + hard_amt) > land_mob_max)
 	hard_amt = land_mob_max - lp->lnd_harden;
 
-    eng = is_engineer(lp->lnd_x, lp->lnd_y);
+    eng = has_helpful_engineer(lp->lnd_x, lp->lnd_y, lp->lnd_own);
 
     if (eng)
 	hard_amt = ((float)hard_amt * 1.5);