diff --git a/var/spack/repos/builtin/packages/bzip2/package.py b/var/spack/repos/builtin/packages/bzip2/package.py
index 6e27c333165..c39cbcdabd2 100644
--- a/var/spack/repos/builtin/packages/bzip2/package.py
+++ b/var/spack/repos/builtin/packages/bzip2/package.py
@@ -101,16 +101,19 @@ def patch(self):
                 **kwargs)
 
     def install(self, spec, prefix):
-        if self.spec.satisfies('%emscripten'):
-            make = emmake
+        def do_make(*args):
+            if self.spec.satisfies('%emscripten'):
+                emmake(*args)
+            else:
+                make(*args)
 
         # Build the dynamic library first
         if '+shared' in spec:
-            make('-f', 'Makefile-libbz2_so')
+            do_make('-f', 'Makefile-libbz2_so')
 
         # Build the static library and everything else
-        make()
-        make('install', 'PREFIX={0}'.format(prefix))
+        do_make()
+        do_make('install', 'PREFIX={0}'.format(prefix))
 
         if self.spec.satisfies('%emscripten'):
             install('bzip2.wasm',
diff --git a/var/spack/repos/builtin/packages/zlib/package.py b/var/spack/repos/builtin/packages/zlib/package.py
index 07a3cd6d87c..3fee67a6f32 100644
--- a/var/spack/repos/builtin/packages/zlib/package.py
+++ b/var/spack/repos/builtin/packages/zlib/package.py
@@ -75,16 +75,23 @@ def install(self, spec, prefix):
             nmake('-f' 'win32\\Makefile.msc')
             self.win_install()
         else:
-            if self.spec.satisfies('%emscripten'):
-                configure = emconfigure
-                make = emmake
+            def do_configure(*args):
+                if self.spec.satisfies('%emscripten'):
+                    emconfigure(*args)
+                else:
+                    configure(*args)
+            def do_make(*args):
+                if self.spec.satisfies('%emscripten'):
+                    emmake(*args)
+                else:
+                    make(*args)
 
             config_args = []
             if '~shared' in spec:
                 config_args.append('--static')
-            configure('--prefix={0}'.format(prefix), *config_args)
+            do_configure('--prefix={0}'.format(prefix), *config_args)
 
-            make()
+            do_make()
             if self.run_tests:
-                make('check')
-            make('install')
+                do_make('check')
+            do_make('install')