diff --git a/Makefile b/Makefile
index 8a833ce..9f2be65 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,7 @@ LDLIBS += -lpcap -lpthread #-lefence
 # Optional C compiler and linker flags. Typical driftnet builds have support
 # for displaying captured images in an X window, and need the following flags:
 CFLAGS  += `pkg-config --cflags gtk+-2.0` `pkg-config --cflags libpng`
-LDLIBS  += -ljpeg -lgif `pkg-config --libs gtk+-2.0` `pkg-config --cflags libpng`
+LDLIBS  += -ljpeg -lgif `pkg-config --libs gtk+-2.0` `pkg-config --libs libpng`
 
 # Alternatively, you can build a version of driftnet which can only be used
 # in `adjunct' mode as the back end for some other image-processing program. To
diff --git a/png.c b/png.c
index 6c0a23b..f001d7f 100644
--- a/png.c
+++ b/png.c
@@ -104,7 +104,7 @@ int png_load_img(img I) {
     if (color_type == PNG_COLOR_TYPE_GRAY ||
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
         if (bit_depth < 8) {
-            png_set_gray_1_2_4_to_8(png_ptr);
+            png_set_expand_gray_1_2_4_to_8(png_ptr);
         }
         png_set_gray_to_rgb(png_ptr);
     }