diff --git a/pkgs/development/libraries/ffmpeg-full/default.nix b/pkgs/development/libraries/ffmpeg-full/default.nix
index 2bb55102aa2f..05da125dd266 100644
--- a/pkgs/development/libraries/ffmpeg-full/default.nix
+++ b/pkgs/development/libraries/ffmpeg-full/default.nix
@@ -420,8 +420,8 @@ stdenv.mkDerivation rec {
                                    MediaToolbox VideoDecodeAcceleration
                                    libiconv cf-private /* For _OBJC_EHTYPE_$_NSException */ ];
 
-  # Build qt-faststart executable
-  buildPhase = optional qtFaststartProgram ''make tools/qt-faststart'';
+  buildFlags = [ "all" ]
+    ++ optional qtFaststartProgram "tools/qt-faststart"; # Build qt-faststart executable
 
   # Hacky framework patching technique borrowed from the phantomjs2 package
   postInstall = optionalString qtFaststartProgram ''