diff --git a/test/stub-test.sh b/test/stub-test.sh
index cc08a2c..69bd23b 100755
--- a/test/stub-test.sh
+++ b/test/stub-test.sh
@@ -29,11 +29,13 @@ my-name-is() { echo "My name is $@."; }
 stub "my-name-is" STDERR
 assert "my-name-is Edward" ""
 assert "my-name-is Edward 2>&1" "my-name-is stub: Edward"
+unset -f my-name-is
 
 
 # Stubbing something that doesn't exist.
 stub "cowabunga-dude"
 assert "cowabunga-dude yeah dude" "cowabunga-dude stub: yeah dude"
+unset -f cowabunga-dude
 
 
 # End of tests.
diff --git a/test/stub_and_echo-test.sh b/test/stub_and_echo-test.sh
index fe1632a..3846d3f 100755
--- a/test/stub_and_echo-test.sh
+++ b/test/stub_and_echo-test.sh
@@ -29,12 +29,14 @@ my-name-is() { echo "My name is $@."; }
 stub_and_echo "my-name-is" "Hohenheim" STDERR
 assert "my-name-is Edward" ""
 assert "my-name-is Edward 2>&1" "Hohenheim"
+unset -f my-name-is
 
 
 # Stubbing something that doesn't exist.
 stub_and_echo "cowabunga-dude" "Surf's up dude :D"
 assert "cowabunga-dude" "Surf's up dude :D"
 assert "cowabunga-dude yeah dude" "Surf's up dude :D"
+unset -f cowabunga-dude
 
 
 # End of tests.
diff --git a/test/stub_and_eval-test.sh b/test/stub_and_eval-test.sh
index e1cba97..263524c 100755
--- a/test/stub_and_eval-test.sh
+++ b/test/stub_and_eval-test.sh
@@ -28,6 +28,7 @@ unset -f uname
 stub_and_eval "cowabunga-dude" "date +%Y"
 assert "cowabunga-dude" "$(date +%Y)"
 assert "cowabunga-dude yeah dude" "$(date +%Y)"
+unset -f cowabunga-dude
 
 
 # End of tests.