diff --git a/platform/osx/os_osx.mm b/platform/osx/os_osx.mm
index c9a07f34ea5..b60cf740945 100644
--- a/platform/osx/os_osx.mm
+++ b/platform/osx/os_osx.mm
@@ -1226,7 +1226,7 @@ void OS_OSX::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, c
 
 		Image image = texture->get_data();
 
-		NSBitmapImageRep *imgrep = [[[NSBitmapImageRep alloc]
+		NSBitmapImageRep *imgrep = [[NSBitmapImageRep alloc]
 				initWithBitmapDataPlanes:NULL
 							  pixelsWide:int(texture_size.width)
 							  pixelsHigh:int(texture_size.height)
@@ -1236,7 +1236,7 @@ void OS_OSX::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, c
 								isPlanar:NO
 						  colorSpaceName:NSDeviceRGBColorSpace
 							 bytesPerRow:int(texture_size.width) * 4
-							bitsPerPixel:32] autorelease];
+							bitsPerPixel:32];
 		ERR_FAIL_COND(imgrep == nil);
 		uint8_t *pixels = [imgrep bitmapData];
 
@@ -1263,9 +1263,10 @@ void OS_OSX::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, c
 			pixels[i * 4 + 3] = alpha;
 		}
 
-		NSImage *nsimage = [[[NSImage alloc] initWithSize:NSMakeSize(texture_size.width, texture_size.height)] autorelease];
+		NSImage *nsimage = [[NSImage alloc] initWithSize:NSMakeSize(texture_size.width, texture_size.height)];
 		[nsimage addRepresentation:imgrep];
 
+		[cursors[p_shape] release];
 		NSCursor *cursor = [[NSCursor alloc] initWithImage:nsimage hotSpot:NSMakePoint(p_hotspot.x, p_hotspot.y)];
 
 		cursors[p_shape] = cursor;
@@ -1273,6 +1274,9 @@ void OS_OSX::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, c
 		if (p_shape == CURSOR_ARROW) {
 			[cursor set];
 		}
+
+		[imgrep release];
+		[nsimage release];
 	}
 }
 
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index 357ade8a919..178f603114d 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -2017,7 +2017,7 @@ void OS_Windows::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shap
 		UINT size = sizeof(UINT) * image_size;
 
 		// Create the BITMAP with alpha channel
-		COLORREF *buffer = (COLORREF *)malloc(sizeof(COLORREF) * image_size);
+		COLORREF *buffer = (COLORREF *)memalloc(sizeof(COLORREF) * image_size);
 
 		for (UINT index = 0; index < image_size; index++) {
 			int row_index = floor(index / texture_size.width) + atlas_rect.pos.y;
@@ -2042,6 +2042,8 @@ void OS_Windows::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shap
 		GetMaskBitmaps(bitmap, clrTransparent, hAndMask, hXorMask);
 
 		if (NULL == hAndMask || NULL == hXorMask) {
+			memfree(buffer);
+			DeleteObject(bitmap);
 			return;
 		}
 
@@ -2066,6 +2068,9 @@ void OS_Windows::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shap
 		if (hXorMask != NULL) {
 			DeleteObject(hXorMask);
 		}
+
+		memfree(buffer);
+		DeleteObject(bitmap);
 	}
 }
 
diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp
index 3356c8341d1..ecbdf9b41ea 100644
--- a/platform/x11/os_x11.cpp
+++ b/platform/x11/os_x11.cpp
@@ -2198,7 +2198,7 @@ void OS_X11::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, c
 		cursor_image->yhot = p_hotspot.y;
 
 		// allocate memory to contain the whole file
-		cursor_image->pixels = (XcursorPixel *)malloc(size);
+		cursor_image->pixels = (XcursorPixel *)memalloc(size);
 
 		for (XcursorPixel index = 0; index < image_size; index++) {
 			int row_index = floor(index / texture_size.width) + atlas_rect.pos.y;
@@ -2220,6 +2220,9 @@ void OS_X11::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, c
 		if (p_shape == CURSOR_ARROW) {
 			XDefineCursor(x11_display, x11_window, cursors[p_shape]);
 		}
+
+		memfree(cursor_image->pixels);
+		XcursorImageDestroy(cursor_image);
 	}
 }