diff --git a/data/test/scenarios/filter_vision.cfg b/data/test/scenarios/filter_vision.cfg
new file mode 100644
index 000000000000..49acb0f0d8c4
--- /dev/null
+++ b/data/test/scenarios/filter_vision.cfg
@@ -0,0 +1,157 @@
+# This test scenario checks unit filter [filter_vision],
+# and terrain_filter [filter_vision]. It tests what happens
+# when there is a single, there are multiple, or there are 
+# no matches to the standard side filter contained.
+
+#define TEST_FILTER_VISION_SCEN ID EVENTS
+    [test]
+        name = "Unit Test {ID}"
+        map_data = "{test/maps/move_skip_sighted.map}"
+        turns = 3
+        id = {ID}
+        random_start_time = no
+
+        {DAWN}
+
+        [side]
+            side=1
+            controller=human
+            name = "Alice"
+            type = Elvish Archer
+            id=alice
+            fog=yes
+            team_name=West
+        [/side]
+        [side]
+            side=2
+            controller=human
+            name = "Bob"
+            type = Orcish Grunt
+            id=bob
+            fog=yes
+            team_name=East
+        [/side]
+        [side]
+            side=3
+            controller=human
+            name = "Dave"
+            type = Dwarvish Fighter
+            id=dave
+            fog=yes
+            team_name=East
+        [/side]
+        [side]
+            side=4
+            controller=human
+            name = "Charlie"
+            type = Chocobone
+            id=charlie
+            fog=yes
+            team_name=West
+        [/side]
+
+	{EVENTS}
+    [/test]
+#enddef
+
+#define chat_if X
+{VARIABLE_OP chat_ctr add 1}
+
+[if]
+    {X}
+    [then]
+        [chat]
+             message="$chat_ctr" ": yes"
+        [/chat]
+    [/then]
+    [else]
+        [chat]
+             message="$chat_ctr" ": no"
+        [/chat]
+    [/else]
+[/if]
+#enddef
+
+#define test_vision_chat X Y
+{chat_if ([have_unit]
+           {X}
+           [filter_vision]
+               {Y}
+           [/filter_vision]
+       [/have_unit]
+   )}
+{chat_if ([have_unit]
+           {X}
+           [filter_location]
+               [filter_vision]
+                   {Y}
+               [/filter_vision]
+           [/filter_location]
+       [/have_unit]
+   )}
+[delay]
+    time=500
+[/delay]
+#enddef
+
+#define assert_test_true X Y
+{ASSERT ([have_unit]
+           {X}
+           [filter_vision]
+               {Y}
+           [/filter_vision]
+       [/have_unit]
+   )}
+{ASSERT ([have_unit]
+           {X}
+           [filter_location]
+               [filter_vision]
+                   {Y}
+               [/filter_vision]
+           [/filter_location]
+       [/have_unit]
+   )}
+#enddef
+
+#define assert_test_false X Y
+{ASSERT ([not]
+           [have_unit]
+               {X}
+               [filter_vision]
+                   {Y}
+               [/filter_vision]
+           [/have_unit]
+       [/not]
+   )}
+{ASSERT ([not]
+           [have_unit]
+               {X}
+               [filter_location]
+                   [filter_vision]
+                       {Y}
+                   [/filter_vision]
+               [/filter_location]
+           [/have_unit]
+       [/not]
+   )}
+#enddef
+
+{TEST_FILTER_VISION_SCEN "filter_vision" (
+    [event]
+        name=start
+        {VARIABLE chat_ctr 0}
+
+        {assert_test_true () (side=1,2,3,4)}
+        {assert_test_true (side=2) (side=1,2,3,4)}
+        {assert_test_true (side=4) (side=1,2,3,4)}
+        {assert_test_true (side=1) (side=4)}
+        {assert_test_true (side=2) (side=4)}
+        {assert_test_true (side=3) (side=4)}
+        {assert_test_true (side=4) (side=1)}
+        {assert_test_true (side=4) (side=3)}
+        {assert_test_false (side=4) (side=2)}
+        {assert_test_false () (side=5)}
+
+        {RETURN ([true][/true])}
+    [/event]
+)}
diff --git a/src/terrain_filter.cpp b/src/terrain_filter.cpp
index 4fca2af732ff..216c9b651da0 100644
--- a/src/terrain_filter.cpp
+++ b/src/terrain_filter.cpp
@@ -183,13 +183,16 @@ bool terrain_filter::match_internal(const map_location& loc, const bool ignore_x
 			side_filter ssf(*i, fc_);
 			std::vector<int> sides = ssf.get_teams();
 
+			bool found = false;
 			BOOST_FOREACH(const int side, sides) {
 				const team &viewing_team = fc_->get_disp_context().teams().at(side - 1);
 				bool viewer_sees = respect_fog ? !viewing_team.fogged(loc) : !viewing_team.shrouded(loc);
-				if (visible != viewer_sees) {
-					return false;
+				if (visible == viewer_sees) {
+					found = true;
+					break;
 				}
 			}
+			if (!found) {return false;}
 		}
 	}
 
diff --git a/src/unit_filter.cpp b/src/unit_filter.cpp
index 28ad001fcc59..98e46b1e9588 100644
--- a/src/unit_filter.cpp
+++ b/src/unit_filter.cpp
@@ -531,16 +531,18 @@ bool basic_unit_filter_impl::internal_matches_filter(const unit & u, const map_l
 	assert(vision_filters_viewers_lists_.size() == vision_filters_visible_attr_.size());
 	for (size_t i = 0; i < vision_filters_viewers_lists_.size(); i++) {
 		const std::set<int> & viewers = vision_filters_viewers_lists_[i];
-		if (viewers.empty()) {
-			return false;
-		}
-		std::set<int>::const_iterator viewer, viewer_end = viewers.end();
-		for (viewer = viewers.begin(); viewer != viewer_end; ++viewer) {
-			bool fogged = fc_.get_disp_context().teams()[*viewer - 1].fogged(loc);
+
+		bool found = false;
+		BOOST_FOREACH (const int viewer, viewers) {
+			bool fogged = fc_.get_disp_context().teams()[viewer - 1].fogged(loc);
 			bool hiding = u.invisible(loc/*, false(?) */);
 			bool unit_hidden = fogged || hiding;
-			if (vision_filters_visible_attr_[i] == unit_hidden) return false;
+			if (vision_filters_visible_attr_[i] != unit_hidden) {
+				found = true;
+				break;
+			}
 		}
+		if (!found) {return false;}
 	}
 
 	assert(filter_adj_filters_.size() == filter_adj_is_enemy_.size());
diff --git a/wml_test_schedule b/wml_test_schedule
index 4676a25fd16f..d277aa2ac3cb 100644
--- a/wml_test_schedule
+++ b/wml_test_schedule
@@ -79,6 +79,7 @@
 0 event_handlers_in_events_6
 0 event_handlers_in_events_7
 0 event_handlers_in_events_8
+0 filter_vision
 #
 # Pathfinding
 #