diff --git a/src/osgPlugins/png/ReaderWriterPNG.cpp b/src/osgPlugins/png/ReaderWriterPNG.cpp
index 4d9121a5d..f007a9751 100644
--- a/src/osgPlugins/png/ReaderWriterPNG.cpp
+++ b/src/osgPlugins/png/ReaderWriterPNG.cpp
@@ -112,14 +112,15 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
             //Set compression level
             png_set_compression_level(png, compression_level);
 
+            int bit_depth = img.getPixelSizeInBits();
             switch(img.getPixelFormat()) {
                 case(GL_LUMINANCE): color = PNG_COLOR_TYPE_GRAY; break;
                 case(GL_ALPHA): color = PNG_COLOR_TYPE_GRAY; break; //Couldn't find a color type for pure alpha, using gray instead
-                case(GL_LUMINANCE_ALPHA): color = PNG_COLOR_TYPE_GRAY_ALPHA ; break;
-                case(GL_RGB): color = PNG_COLOR_TYPE_RGB; break;
-                case(GL_RGBA): color = PNG_COLOR_TYPE_RGB_ALPHA; break;
-                case(GL_BGR): color = PNG_COLOR_TYPE_RGB; png_set_bgr(png); break;
-                case(GL_BGRA): color = PNG_COLOR_TYPE_RGB_ALPHA; png_set_bgr(png); break;
+                case(GL_LUMINANCE_ALPHA): color = PNG_COLOR_TYPE_GRAY_ALPHA ; bit_depth /= 2; break;
+                case(GL_RGB): color = PNG_COLOR_TYPE_RGB; bit_depth /= 3; break;
+                case(GL_RGBA): color = PNG_COLOR_TYPE_RGB_ALPHA; bit_depth /= 4; break;
+                case(GL_BGR): color = PNG_COLOR_TYPE_RGB; png_set_bgr(png); bit_depth /= 3; break;
+                case(GL_BGRA): color = PNG_COLOR_TYPE_RGB_ALPHA; png_set_bgr(png); bit_depth /= 4; break;
                 default: return WriteResult::ERROR_IN_WRITING_FILE; break;
             }
 
@@ -131,7 +132,7 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
 
             //Write header info
             png_set_IHDR(png, info, img.s(), img.t(),
-                        8, color, PNG_INTERLACE_NONE,
+                        bit_depth, color, PNG_INTERLACE_NONE,
                         PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
             png_write_info(png, info);