diff --git a/lib/spack/spack/packages/callpath.py b/lib/spack/spack/packages/callpath.py
index 3d79940b6e0bcf9a309f64ed10aed0e36bf3866c..689cdb832debed82b8822175413c0c9e6f64aefc 100644
--- a/lib/spack/spack/packages/callpath.py
+++ b/lib/spack/spack/packages/callpath.py
@@ -8,6 +8,6 @@ class Callpath(Package):
     depends_on("mpi")
 
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix)
+        configure("--prefix=" + prefix)
         make()
         make("install")
diff --git a/lib/spack/spack/packages/cmake.py b/lib/spack/spack/packages/cmake.py
index 3ee294b134bd3c3314fbb74c1537a9970e22232d..3d98567f71753a7baecec7b560ffead6faa8d3f8 100644
--- a/lib/spack/spack/packages/cmake.py
+++ b/lib/spack/spack/packages/cmake.py
@@ -6,7 +6,7 @@ class Cmake(Package):
     versions  = { '2.8.10.2' : '097278785da7182ec0aea8769d06860c' }
 
     def install(self, spec, prefix):
-        configure('--prefix=%s'   % prefix,
-                  '--parallel=%s' % make_jobs)
+        configure('--prefix='   + prefix,
+                  '--parallel=' + make_jobs)
         make()
         make('install')
diff --git a/lib/spack/spack/packages/dyninst.py b/lib/spack/spack/packages/dyninst.py
index 187cc2bb5ab99da3739bf774e4d560882bf1213c..20dbddeb7a0de88990714f5e5a32a84b9ed45b41 100644
--- a/lib/spack/spack/packages/dyninst.py
+++ b/lib/spack/spack/packages/dyninst.py
@@ -12,6 +12,6 @@ class Dyninst(Package):
     depends_on("libdwarf")
 
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix)
+        configure("--prefix=" + prefix)
         make()
         make("install")
diff --git a/lib/spack/spack/packages/libdwarf.py b/lib/spack/spack/packages/libdwarf.py
index 3102c3d4dd65c9150643f1b8a887ce6c3abec637..3fd727257dadd8de94b9876753512774472c2039 100644
--- a/lib/spack/spack/packages/libdwarf.py
+++ b/lib/spack/spack/packages/libdwarf.py
@@ -31,7 +31,7 @@ def install(self, spec, prefix):
         mkdirp(prefix.bin, prefix.include, prefix.lib, prefix.man1)
 
         with working_dir('libdwarf'):
-            configure("--prefix=%s" % prefix, '--enable-shared')
+            configure("--prefix=" + prefix, "--enable-shared")
             make()
 
             install('libdwarf.a',  prefix.lib)
@@ -40,7 +40,7 @@ def install(self, spec, prefix):
             install('dwarf.h',     prefix.include)
 
         with working_dir('dwarfdump2'):
-            configure("--prefix=%s" % prefix)
+            configure("--prefix=" + prefix)
 
             # This makefile has strings of copy commands that
             # cause a race in parallel
diff --git a/lib/spack/spack/packages/libelf.py b/lib/spack/spack/packages/libelf.py
index ec2c4a6c0f829390771d67488cdf53069c33c991..1ef911d6c872c19891508a23007b2cfef57af808 100644
--- a/lib/spack/spack/packages/libelf.py
+++ b/lib/spack/spack/packages/libelf.py
@@ -13,7 +13,7 @@ class Libelf(Package):
                  '0.8.12' : 'e21f8273d9f5f6d43a59878dc274fec7', }
 
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix,
+        configure("--prefix=" + prefix,
                   "--enable-shared",
                   "--disable-dependency-tracking",
                   "--disable-debug")
diff --git a/lib/spack/spack/packages/libunwind.py b/lib/spack/spack/packages/libunwind.py
index 0366ebefbab296619ca1c5809ad07f16e96eed4d..817ead97daf1db7b2957023127820c49f25fab10 100644
--- a/lib/spack/spack/packages/libunwind.py
+++ b/lib/spack/spack/packages/libunwind.py
@@ -7,6 +7,6 @@ class Libunwind(Package):
     versions = { '1.1' : 'fb4ea2f6fbbe45bf032cd36e586883ce' }
 
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix)
+        configure("--prefix=" + prefix)
         make()
         make("install")
diff --git a/lib/spack/spack/packages/mpich.py b/lib/spack/spack/packages/mpich.py
index a21db55fe887d5145db98730af0b37301a688ee2..897a11c56426d2a0fe94b6f1e8f9f0779b5949ed 100644
--- a/lib/spack/spack/packages/mpich.py
+++ b/lib/spack/spack/packages/mpich.py
@@ -14,6 +14,6 @@ class Mpich(Package):
     provides('mpi@:1', when='@1:')
 
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix)
+        configure("--prefix=" + prefix)
         make()
         make("install")
diff --git a/lib/spack/spack/packages/mpileaks.py b/lib/spack/spack/packages/mpileaks.py
index 25036a0d53b379aa1afa1f57450ff0c2797f4b73..28124911b4ee8dade323262399f69113de96ecb2 100644
--- a/lib/spack/spack/packages/mpileaks.py
+++ b/lib/spack/spack/packages/mpileaks.py
@@ -8,6 +8,6 @@ class Mpileaks(Package):
     depends_on("callpath")
 
     def install(self, spec, prefix):
-        configure("--prefix=%s" % prefix)
+        configure("--prefix=" + prefix)
         make()
         make("install")