diff --git a/src/map.cpp b/src/map.cpp
index e1ffc2550..0ce43a573 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -238,7 +238,9 @@ unsigned Map::height() const
 
 void Map::set_width(unsigned width)
 {
-    if (width >= MIN_MAPSIZE && width <= MAX_MAPSIZE)
+    if (width != width_ &&
+        width >= MIN_MAPSIZE &&
+        width <= MAX_MAPSIZE)
     {
         width_=width;
         fixAspectRatio();
@@ -247,7 +249,9 @@ void Map::set_width(unsigned width)
 
 void Map::set_height(unsigned height)
 {
-    if (height >= MIN_MAPSIZE && height <= MAX_MAPSIZE)
+    if (height != height_ &&
+        height >= MIN_MAPSIZE &&
+        height <= MAX_MAPSIZE)
     {
         height_=height;
         fixAspectRatio();
@@ -256,8 +260,12 @@ void Map::set_height(unsigned height)
 
 void Map::resize(unsigned width,unsigned height)
 {
-    if (width >= MIN_MAPSIZE && width <= MAX_MAPSIZE &&
-        height >= MIN_MAPSIZE && height <= MAX_MAPSIZE)
+    if (width != width_ &&
+        height != height_ &&
+        width >= MIN_MAPSIZE &&
+        width <= MAX_MAPSIZE &&
+        height >= MIN_MAPSIZE &&
+        height <= MAX_MAPSIZE)
     {
         width_=width;
         height_=height;