diff --git a/examples/script-overrides/git-extract-submodules/git-extract.sh b/examples/script-overrides/git-extract-submodules/git-extract.sh
index d258de4..477865b 100644
--- a/examples/script-overrides/git-extract-submodules/git-extract.sh
+++ b/examples/script-overrides/git-extract-submodules/git-extract.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This script is called from lib/octocatalog-diff/catalog-util/git.rb and is used to
 # archive and extract a certain branch of a git repository into a target directory.
diff --git a/script/fmt b/script/fmt
index e130b01..2576e8b 100755
--- a/script/fmt
+++ b/script/fmt
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && cd .. && pwd )"
 RUBOCOP_YML="${DIR}/.rubocop.yml"
diff --git a/script/git-pre-commit b/script/git-pre-commit
index 64c997f..88f4a60 100755
--- a/script/git-pre-commit
+++ b/script/git-pre-commit
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This script is being invoked via <root dir>/.git/hooks, hence the
 # base directory is up two levels, not just one.
diff --git a/script/octocatalog-diff-wrapper b/script/octocatalog-diff-wrapper
index 8f3104b..090648a 100755
--- a/script/octocatalog-diff-wrapper
+++ b/script/octocatalog-diff-wrapper
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This script exists to make it easier to test alternate branches of octocatalog-diff.
 # It is intended as a one-for-one replacement of `octocatalog-diff` as installed by the gem.
diff --git a/script/puppet b/script/puppet
index a6d58b6..af4705f 100755
--- a/script/puppet
+++ b/script/puppet
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && cd .. && pwd )"
 
diff --git a/scripts/env/env.sh b/scripts/env/env.sh
index d1169f8..c08b4b6 100644
--- a/scripts/env/env.sh
+++ b/scripts/env/env.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This script echoes back the environment. This is used for spec testing
 # and possible debugging.
diff --git a/scripts/git-extract/git-extract.sh b/scripts/git-extract/git-extract.sh
index 7c8255a..cabe54b 100644
--- a/scripts/git-extract/git-extract.sh
+++ b/scripts/git-extract/git-extract.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This script is called from lib/octocatalog-diff/catalog-util/git.rb and is used to
 # archive and extract a certain branch of a git repository into a target directory.
diff --git a/scripts/puppet/puppet.sh b/scripts/puppet/puppet.sh
index 0a2b6a7..1b829e6 100644
--- a/scripts/puppet/puppet.sh
+++ b/scripts/puppet/puppet.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Script to run Puppet. The default implementation here is simply to pass
 # through the command line arguments (which are likely to be numerous when
diff --git a/spec/octocatalog-diff/fixtures/override-scripts/git-extract.sh b/spec/octocatalog-diff/fixtures/override-scripts/git-extract.sh
index 380d835..e6d9302 100644
--- a/spec/octocatalog-diff/fixtures/override-scripts/git-extract.sh
+++ b/spec/octocatalog-diff/fixtures/override-scripts/git-extract.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # For test purposes only, this script would ordinarily run a git checkout, but here
 # it's going to generate a directory structure by copying some other fixture.
diff --git a/spec/octocatalog-diff/tests/bootstrap_spec.rb b/spec/octocatalog-diff/tests/bootstrap_spec.rb
index a5acd06..af88f97 100644
--- a/spec/octocatalog-diff/tests/bootstrap_spec.rb
+++ b/spec/octocatalog-diff/tests/bootstrap_spec.rb
@@ -71,10 +71,11 @@ describe OctocatalogDiff::Bootstrap do
       end
 
       it 'should execute bootstrap script with PATH matching environment' do
-        ENV['PATH'] = @d + '/adslfk'
+        old_path = ENV['PATH']
+        ENV['PATH'] = "#{old_path}:#{@d + '/adslfk'}"
         result = b(path: @d, bootstrap_script: 'script/bootstrap.sh', bootstrap_args: 'PATH')
         expect(result[:status_code]).to eq(32)
-        expect(result[:output].strip).to eq(@d + '/adslfk')
+        expect(result[:output].strip).to eq("#{old_path}:#{@d + '/adslfk'}")
       end
 
       it 'should execute bootstrap script with BASEDIR matching argument' do
diff --git a/spec/octocatalog-diff/tests/spec_helper.rb b/spec/octocatalog-diff/tests/spec_helper.rb
index 8478979..0108298 100644
--- a/spec/octocatalog-diff/tests/spec_helper.rb
+++ b/spec/octocatalog-diff/tests/spec_helper.rb
@@ -183,7 +183,7 @@ module OctocatalogDiff
       temp_repo_dir = Dir.mktmpdir
       Dir.mkdir(File.join(temp_repo_dir, 'script'))
       File.open(File.join(temp_repo_dir, 'script', filename), 'w') do |f|
-        f.write "#!/bin/bash\n"
+        f.write "#!/usr/bin/env bash\n"
         f.write "var=\"${@: -1}\"\n"
         f.write "if [ \"$var\" = \"\" ]; then exit 31; fi\n"
         f.write "eval answer=\\$$var\n"