diff --git a/audio/clam_voice2midi/clam_voice2midi.SlackBuild b/audio/clam_voice2midi/clam_voice2midi.SlackBuild
index 752826ae60..c4b91051be 100644
--- a/audio/clam_voice2midi/clam_voice2midi.SlackBuild
+++ b/audio/clam_voice2midi/clam_voice2midi.SlackBuild
@@ -4,6 +4,8 @@
 
 # Written by B. Watson (yalhcru@gmail.com)
 
+# Licensed under the WTFPL. See http://www.wtfpl.net/txt/copying/ for details.
+
 PRGNAM=clam_voice2midi
 VERSION=${VERSION:-0.3.10}
 BUILD=${BUILD:-2}
@@ -67,7 +69,7 @@ patch -p1 < $CWD/fix_undelinking.patch
 
 CCFLAGS="$SLKCFLAGS" \
 CPPFLAGS="$SLKCFLAGS" \
-	scons \
+	scons $MAKEFLAGS \
 	prefix=/usr \
 	release=yes \
 	clam_prefix=/usr
diff --git a/audio/clam_voice2midi/fix_undelinking.patch b/audio/clam_voice2midi/fix_undelinking.patch
index 3818e0074e..b84fb1e9d4 100644
--- a/audio/clam_voice2midi/fix_undelinking.patch
+++ b/audio/clam_voice2midi/fix_undelinking.patch
@@ -6,7 +6,7 @@ diff -Naur Voice2MIDI-0.3.10.orig/SConstruct Voice2MIDI-0.3.10/SConstruct
  if sys.platform == 'darwin' :
  	extralinkFlags=['-dynamic','-bind_at_load']
 +if sys.platform == 'linux2' :
-+	extralinkFlags=['-lGL']
++	extralinkFlags=['-lGL', '-lpthread']
  
  programs = []
  for main in mainSources.items() :