diff --git a/tests/common.sh b/tests/common.sh
index d57621d..d97a347 100644
--- a/tests/common.sh
+++ b/tests/common.sh
@@ -1,3 +1,4 @@
+#!/bin/sh
 export test_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
 export repo_dir="$test_dir/.."
 export NVM_DIR="$repo_dir/.nvm"
diff --git a/tests/loading/Check zsh-nvm doesn't install nvm if it's already installed b/tests/loading/Check zsh-nvm doesn't install nvm if it's already installed
index c1a39aa..90389e6 100755
--- a/tests/loading/Check zsh-nvm doesn't install nvm if it's already installed	
+++ b/tests/loading/Check zsh-nvm doesn't install nvm if it's already installed	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 nvm_placeholder="nvm placeholder"
diff --git a/tests/loading/Check zsh-nvm exports NVM_DIR if it doesn't exist b/tests/loading/Check zsh-nvm exports NVM_DIR if it doesn't exist
index 7500da6..5f4d28c 100755
--- a/tests/loading/Check zsh-nvm exports NVM_DIR if it doesn't exist	
+++ b/tests/loading/Check zsh-nvm exports NVM_DIR if it doesn't exist	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # We don't need to actually load nvm for this test
diff --git a/tests/loading/Check zsh-nvm installs nvm if it isn't already installed b/tests/loading/Check zsh-nvm installs nvm if it isn't already installed
index 6421ad9..d35b96e 100755
--- a/tests/loading/Check zsh-nvm installs nvm if it isn't already installed	
+++ b/tests/loading/Check zsh-nvm installs nvm if it isn't already installed	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # Check nvm isn't already installed
diff --git a/tests/loading/Check zsh-nvm is loaded b/tests/loading/Check zsh-nvm is loaded
index ddb675e..45e6562 100755
--- a/tests/loading/Check zsh-nvm is loaded	
+++ b/tests/loading/Check zsh-nvm is loaded	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # We don't need to actually load nvm for this test
diff --git a/tests/loading/Check zsh-nvm loads nvm b/tests/loading/Check zsh-nvm loads nvm
index 0472682..6f5359d 100755
--- a/tests/loading/Check zsh-nvm loads nvm	
+++ b/tests/loading/Check zsh-nvm loads nvm	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # Check nvm isn't already loaded
diff --git a/tests/loading/Check zsh-nvm wraps nvm b/tests/loading/Check zsh-nvm wraps nvm
index d65a5c2..5e18891 100755
--- a/tests/loading/Check zsh-nvm wraps nvm	
+++ b/tests/loading/Check zsh-nvm wraps nvm	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # Load zsh-nvm
diff --git a/tests/loading/teardown b/tests/loading/teardown
index c436201..a5fa35b 100755
--- a/tests/loading/teardown
+++ b/tests/loading/teardown
@@ -1 +1,2 @@
+#!/bin/sh
 rm -rf ../../.nvm
diff --git a/tests/wrapper commands/nvm revert b/tests/wrapper commands/nvm revert
index 478b655..d9c258e 100755
--- a/tests/wrapper commands/nvm revert	
+++ b/tests/wrapper commands/nvm revert	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # Version to revert nvm to
diff --git a/tests/wrapper commands/nvm upgrade b/tests/wrapper commands/nvm upgrade
index 03a1424..44542a1 100755
--- a/tests/wrapper commands/nvm upgrade	
+++ b/tests/wrapper commands/nvm upgrade	
@@ -1,3 +1,4 @@
+#!/bin/sh
 source ../common.sh
 
 # Version to revert nvm to
diff --git a/tests/wrapper commands/teardown b/tests/wrapper commands/teardown
index c436201..a5fa35b 100755
--- a/tests/wrapper commands/teardown	
+++ b/tests/wrapper commands/teardown	
@@ -1 +1,2 @@
+#!/bin/sh
 rm -rf ../../.nvm