diff --git a/.travis.yml b/.travis.yml
index 6d3ef3f..a76b809 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,6 +9,11 @@ before_script:
 script:
   - NVM_DIR=$TRAVIS_BUILD_DIR make TEST_SUITE=$TEST_SUITE URCHIN=/tmp/urchin $SHELL
 env:
+  - SHELL=sh TEST_SUITE=install_script
+  - SHELL=dash TEST_SUITE=install_script
+  - SHELL=bash TEST_SUITE=install_script
+  - SHELL=zsh TEST_SUITE=install_script
+  - SHELL=ksh TEST_SUITE=install_script
   - SHELL=sh TEST_SUITE=fast
   - SHELL=dash TEST_SUITE=fast
   - SHELL=bash TEST_SUITE=fast
@@ -34,4 +39,3 @@ env:
   - SHELL=zsh TEST_SUITE=installation WITHOUT_CURL=1
   - SHELL=ksh TEST_SUITE=installation
   - SHELL=ksh TEST_SUITE=installation WITHOUT_CURL=1
-
diff --git a/install.sh b/install.sh
index 85deb51..235b814 100755
--- a/install.sh
+++ b/install.sh
@@ -66,66 +66,79 @@ install_nvm_as_script() {
   }
 }
 
-if [ -z "$METHOD" ]; then
-  # Autodetect install method
-  if nvm_has "git"; then
+nvm_do_install() {
+  if [ -z "$METHOD" ]; then
+    # Autodetect install method
+    if nvm_has "git"; then
+      install_nvm_from_git
+    elif nvm_has "nvm_download"; then
+      install_nvm_as_script
+    else
+      echo >&2 "You need git, curl, or wget to install nvm"
+      exit 1
+    fi
+  elif [ "~$METHOD" = "~git" ]; then
+    if ! nvm_has "git"; then
+      echo >&2 "You need git to install nvm"
+      exit 1
+    fi
     install_nvm_from_git
-  elif nvm_has "nvm_download"; then
+  elif [ "~$METHOD" = "~script" ]; then
+    if ! nvm_has "nvm_download"; then
+      echo >&2 "You need curl or wget to install nvm"
+      exit 1
+    fi
     install_nvm_as_script
-  else
-    echo >&2 "You need git, curl, or wget to install nvm"
-    exit 1
   fi
-elif [ "~$METHOD" = "~git" ]; then
-  if ! nvm_has "git"; then
-    echo >&2 "You need git to install nvm"
-    exit 1
-  fi
-  install_nvm_from_git
-elif [ "~$METHOD" = "~script" ]; then
-  if ! nvm_has "nvm_download"; then
-    echo >&2 "You need curl or wget to install nvm"
-    exit 1
-  fi
-  install_nvm_as_script
-fi
 
-echo
-
-# Detect profile file if not specified as environment variable (eg: PROFILE=~/.myprofile).
-if [ -z "$PROFILE" ]; then
-  if [ -f "$HOME/.bashrc" ]; then
-    PROFILE="$HOME/.bashrc"
-  elif [ -f "$HOME/.bash_profile" ]; then
-    PROFILE="$HOME/.bash_profile"
-  elif [ -f "$HOME/.zshrc" ]; then
-    PROFILE="$HOME/.zshrc"
-  elif [ -f "$HOME/.profile" ]; then
-    PROFILE="$HOME/.profile"
-  fi
-fi
-
-SOURCE_STR="\nexport NVM_DIR=\"$NVM_DIR\"\n[ -s \"\$NVM_DIR/nvm.sh\" ] && . \"\$NVM_DIR/nvm.sh\"  # This loads nvm"
-
-if [ -z "$PROFILE" ] || [ ! -f "$PROFILE" ] ; then
-  if [ -z "$PROFILE" ]; then
-    echo "=> Profile not found. Tried ~/.bashrc, ~/.bash_profile, ~/.zshrc, and ~/.profile."
-    echo "=> Create one of them and run this script again"
-  else
-    echo "=> Profile $PROFILE not found"
-    echo "=> Create it (touch $PROFILE) and run this script again"
-  fi
-  echo "   OR"
-  echo "=> Append the following lines to the correct file yourself:"
-  printf "$SOURCE_STR"
   echo
-else
-  if ! grep -qc 'nvm.sh' "$PROFILE"; then
-    echo "=> Appending source string to $PROFILE"
-    printf "$SOURCE_STR\n" >> "$PROFILE"
-  else
-    echo "=> Source string already in $PROFILE"
-  fi
-fi
 
-echo "=> Close and reopen your terminal to start using nvm"
+  # Detect profile file if not specified as environment variable (eg: PROFILE=~/.myprofile).
+  if [ -z "$PROFILE" ]; then
+    if [ -f "$HOME/.bashrc" ]; then
+      PROFILE="$HOME/.bashrc"
+    elif [ -f "$HOME/.bash_profile" ]; then
+      PROFILE="$HOME/.bash_profile"
+    elif [ -f "$HOME/.zshrc" ]; then
+      PROFILE="$HOME/.zshrc"
+    elif [ -f "$HOME/.profile" ]; then
+      PROFILE="$HOME/.profile"
+    fi
+  fi
+
+  SOURCE_STR="\nexport NVM_DIR=\"$NVM_DIR\"\n[ -s \"\$NVM_DIR/nvm.sh\" ] && . \"\$NVM_DIR/nvm.sh\"  # This loads nvm"
+
+  if [ -z "$PROFILE" ] || [ ! -f "$PROFILE" ] ; then
+    if [ -z "$PROFILE" ]; then
+      echo "=> Profile not found. Tried ~/.bashrc, ~/.bash_profile, ~/.zshrc, and ~/.profile."
+      echo "=> Create one of them and run this script again"
+    else
+      echo "=> Profile $PROFILE not found"
+      echo "=> Create it (touch $PROFILE) and run this script again"
+    fi
+    echo "   OR"
+    echo "=> Append the following lines to the correct file yourself:"
+    printf "$SOURCE_STR"
+    echo
+  else
+    if ! grep -qc 'nvm.sh' "$PROFILE"; then
+      echo "=> Appending source string to $PROFILE"
+      printf "$SOURCE_STR\n" >> "$PROFILE"
+    else
+      echo "=> Source string already in $PROFILE"
+    fi
+  fi
+
+  echo "=> Close and reopen your terminal to start using nvm"
+  nvm_reset
+}
+
+#
+# Unsets the various functions defined
+# during the execution of the install script
+#
+nvm_reset() {
+  unset -f nvm_do_install nvm_has nvm_download install_nvm_as_script install_nvm_from_git nvm_reset
+}
+
+[ "_$NVM_ENV" = "_testing" ] || nvm_do_install
diff --git a/package.json b/package.json
index 8b8ef5c..d5ebb31 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,8 @@
     "test/fast": "urchin -f test/fast",
     "test/slow": "urchin -f test/slow",
     "test/installation": "urchin -f test/installation",
-    "test/sourcing": "urchin -f test/sourcing"
+    "test/sourcing": "urchin -f test/sourcing",
+    "test/install_script": "urchin -f test/install_script"
   },
   "repository": {
     "type": "git",
diff --git a/test/install_script/nvm_do_install b/test/install_script/nvm_do_install
new file mode 100755
index 0000000..02c77f3
--- /dev/null
+++ b/test/install_script/nvm_do_install
@@ -0,0 +1,6 @@
+#!/bin/sh
+
+NVM_ENV=testing . ../../install.sh
+
+#nvm_do_install is available
+type nvm_do_install > /dev/null 2>&1
diff --git a/test/install_script/nvm_reset b/test/install_script/nvm_reset
new file mode 100755
index 0000000..25d9a34
--- /dev/null
+++ b/test/install_script/nvm_reset
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+NVM_ENV=testing . ../../install.sh
+
+safe_type() {
+  type "$1" > /dev/null 2>&1 && return 0 || return 1
+}
+
+# Check nvm_reset exists
+type nvm_reset > /dev/null 2>&1
+
+# Apply nvm_reset
+nvm_reset
+
+# The names should be unset
+! safe_type nvm_do_install && \
+  ! safe_type nvm_has && \
+  ! safe_type nvm_download && \
+  ! safe_type install_nvm_as_script && \
+  ! safe_type install_nvm_from_git && \
+  ! safe_type nvm_reset