diff --git a/source/blender/imbuf/intern/png.c b/source/blender/imbuf/intern/png.c
index b96424dd319..77a0f1dc1db 100644
--- a/source/blender/imbuf/intern/png.c
+++ b/source/blender/imbuf/intern/png.c
@@ -71,7 +71,14 @@ int imb_is_a_png(const unsigned char *mem)
 {
 	int ret_val = 0;
 
-	if (mem) ret_val = !png_sig_cmp(mem, 0, 8);
+	if (mem) {
+#if (PNG_LIBPNG_VER_MAJOR == 1) && (PNG_LIBPNG_VER_MINOR == 2)
+		/* Older version of libpng doesn't use const pointer to memory. */
+		ret_val = !png_sig_cmp((png_bytep)mem, 0, 8);
+#else
+		ret_val = !png_sig_cmp(mem, 0, 8);
+#endif
+	}
 	return(ret_val);
 }