diff --git a/proton b/proton
index 0b06225b..8532c783 100755
--- a/proton
+++ b/proton
@@ -891,6 +891,9 @@ class CompatData:
 
             setup_game_dir_drive()
 
+            # add Steam ffmpeg libraries to path
+            prepend_to_env_str(g_session.env, ld_path_var, steamdir + "/ubuntu12_64/video/:" + steamdir + "/ubuntu12_32/video/", ":")
+
 def comma_escaped(s):
     escaped = False
     idx = -1