diff --git a/libs/gfx/source/pixmap.cpp b/libs/gfx/source/pixmap.cpp
index 47b5fc81..48a033f1 100644
--- a/libs/gfx/source/pixmap.cpp
+++ b/libs/gfx/source/pixmap.cpp
@@ -34,12 +34,16 @@ namespace psemek::gfx
 			fail("P1 format is not supported");
 
 		std::getline(is, line);
+		if (!is)
+			fail("stream error");
 		std::istringstream sline(line);
 
 		std::size_t width, height;
 		pixmap_monochrome pixmap;
 
 		sline >> width >> height;
+		if (!sline)
+			fail("stream error");
 
 		pixmap.resize({width, height});
 
@@ -89,6 +93,8 @@ namespace psemek::gfx
 			fail("unknown format " + line);
 
 		std::getline(is, line);
+		if (!is)
+			fail("stream error");
 		std::istringstream sline(line);
 
 		std::size_t width, height;
@@ -96,10 +102,17 @@ namespace psemek::gfx
 		pixmap_monochrome pixmap;
 
 		sline >> width >> height;
+		if (!sline)
+			fail("stream error");
 
 		std::getline(is, line);
+		if (!is)
+			fail("stream error");
+		sline.clear();
 		sline.str(line);
 		sline >> max;
+		if (!sline)
+			fail("stream error");
 
 		if (max != 255)
 			fail("max value " + std::to_string(max) + " is not supported");
@@ -117,7 +130,7 @@ namespace psemek::gfx
 		return pixmap;
 	}
 
-	pixmap_rgb load_ppm(std::istream & is)
+	pixmap_rgb read_ppm(std::istream & is)
 	{
 		auto fail = [](std::string str)
 		{
@@ -141,6 +154,8 @@ namespace psemek::gfx
 			fail("unknown format " + line);
 
 		std::getline(is, line);
+		if (!is)
+			fail("stream error");
 		std::istringstream sline(line);
 
 		std::size_t width, height;
@@ -149,9 +164,17 @@ namespace psemek::gfx
 
 		sline >> width >> height;
 
+		if (!sline)
+			fail("stream error");
+
 		std::getline(is, line);
+		if (!is)
+			fail("stream error");
+		sline.clear();
 		sline.str(line);
 		sline >> max;
+		if (!sline)
+			fail("stream error");
 
 		if (max != 255)
 			fail("max value " + std::to_string(max) + " is not supported");