diff --git a/install.sh b/install.sh
index 3c33289..73d3ed2 100755
--- a/install.sh
+++ b/install.sh
@@ -42,19 +42,23 @@ nvm_profile_is_bash_or_zsh() {
 # NVM_SOURCE always takes precedence unless the method is "script-nvm-exec"
 #
 nvm_source() {
+  local NVM_GITHUB_REPO
+  NVM_GITHUB_REPO="${NVM_INSTALL_GITHUB_REPO:-nvm-sh/nvm}"
+  local NVM_VERSION
+  NVM_VERSION="${NVM_INSTALL_VERSION:-$(nvm_latest_version)}"
   local NVM_METHOD
   NVM_METHOD="$1"
   local NVM_SOURCE_URL
   NVM_SOURCE_URL="$NVM_SOURCE"
   if [ "_$NVM_METHOD" = "_script-nvm-exec" ]; then
-    NVM_SOURCE_URL="https://raw.githubusercontent.com/nvm-sh/nvm/$(nvm_latest_version)/nvm-exec"
+    NVM_SOURCE_URL="https://raw.githubusercontent.com/${NVM_GITHUB_REPO}/${NVM_VERSION}/nvm-exec"
   elif [ "_$NVM_METHOD" = "_script-nvm-bash-completion" ]; then
-    NVM_SOURCE_URL="https://raw.githubusercontent.com/nvm-sh/nvm/$(nvm_latest_version)/bash_completion"
+    NVM_SOURCE_URL="https://raw.githubusercontent.com/${NVM_GITHUB_REPO}/${NVM_VERSION}/bash_completion"
   elif [ -z "$NVM_SOURCE_URL" ]; then
     if [ "_$NVM_METHOD" = "_script" ]; then
-      NVM_SOURCE_URL="https://raw.githubusercontent.com/nvm-sh/nvm/$(nvm_latest_version)/nvm.sh"
+      NVM_SOURCE_URL="https://raw.githubusercontent.com/${NVM_GITHUB_REPO}/${NVM_VERSION}/nvm.sh"
     elif [ "_$NVM_METHOD" = "_git" ] || [ -z "$NVM_METHOD" ]; then
-      NVM_SOURCE_URL="https://github.com/nvm-sh/nvm.git"
+      NVM_SOURCE_URL="https://github.com/${NVM_GITHUB_REPO}.git"
     else
       echo >&2 "Unexpected value \"$NVM_METHOD\" for \$NVM_METHOD"
       return 1
diff --git a/test/install_script/nvm_install_with_aliased_dot b/test/install_script/nvm_install_with_aliased_dot
index b8f05a5..e1b19a1 100755
--- a/test/install_script/nvm_install_with_aliased_dot
+++ b/test/install_script/nvm_install_with_aliased_dot
@@ -1,6 +1,8 @@
 #!/bin/sh
 
-setup () {
+setup() {
+  # Needed to avoid to checkout the repo to the latest nvm version, losing the commits of the current PR
+  unset NVM_DIR
   shopt -s expand_aliases
   alias .=':'
   NVM_ENV=testing \. ../../install.sh > /dev/null
@@ -12,7 +14,7 @@ cleanup () {
   shopt -u expand_aliases
 }
 
-die () { echo "$@"; exit 1; }
+die () { echo "$@"; cleanup; exit 1; }
 
 setup
 
diff --git a/test/install_script/nvm_install_with_node_version b/test/install_script/nvm_install_with_node_version
index 5f5208f..aef4f0e 100755
--- a/test/install_script/nvm_install_with_node_version
+++ b/test/install_script/nvm_install_with_node_version
@@ -2,6 +2,8 @@
 
 die () { echo "$@" ; exit 1; }
 
+# Needed to avoid to checkout the repo to the latest nvm version, losing the commits of the current PR
+unset NVM_DIR
 NODE_VERSION=8 \. ../../install.sh
 
 # nvm installed node 8
diff --git a/test/install_script/nvm_source b/test/install_script/nvm_source
index 9c1ec08..140afd5 100755
--- a/test/install_script/nvm_source
+++ b/test/install_script/nvm_source
@@ -9,16 +9,20 @@ die () { echo "$@" ; cleanup ; exit 1; }
 NVM_ENV=testing \. ../../install.sh
 
 # nvm_source with no parameter returns the git endpoint
-echo $(nvm_source) | grep "nvm.git$" > /dev/null || die "nvm_source without arguments should return the location of the git repo"
+[ "$(nvm_source)" = "https://github.com/nvm-sh/nvm.git" ] || die "nvm_source without arguments should return the location of the git repo"
+NVM_INSTALL_GITHUB_REPO="other-user/other-nvm" nvm_source | grep "https://github.com/other-user/other-nvm.git$" > /dev/null || die "NVM_INSTALL_GITHUB_REPO=... nvm_source without arguments should return the location of the given git repo"
 
 # nvm_source with git parameter returns the location of the nvm repo
-echo $(nvm_source "git") | grep "nvm.git$" > /dev/null || die "nvm_source without arguments should return the location of the git repo"
+[ "$(nvm_source "git")" = "https://github.com/nvm-sh/nvm.git" ] || die "nvm_source \"git\" should return the location of the git repo"
+NVM_INSTALL_GITHUB_REPO="other-user/other-nvm" nvm_source "git" | grep "https://github.com/other-user/other-nvm.git$" > /dev/null || die "NVM_INSTALL_GITHUB_REPO=... nvm_source \"git\" should return the location of the given git repo"
 
 # nvm_source with script parameter returns the location of nvm.sh
-echo $(nvm_source "script") | grep "nvm.sh$" > /dev/null || die "nvm_source \"script\" should return the location of nvm.sh"
+[ "$(nvm_source "script")" = "https://raw.githubusercontent.com/nvm-sh/nvm/$(nvm_latest_version)/nvm.sh" ] || die "nvm_source \"script\" should return the location of nvm.sh"
+NVM_INSTALL_GITHUB_REPO="other-user/other-nvm" NVM_INSTALL_VERSION="v0.37.0" nvm_source "script" | grep "https://raw.githubusercontent.com/other-user/other-nvm/v0.37.0/nvm.sh$" > /dev/null || die "NVM_INSTALL_GITHUB_REPO=... NVM_INSTALL_VERSION=... nvm_source \"script\" should return the location of nvm.sh"
 
 # nvm_source with script-nvm-exec parameter returns the location of nvm-exec
-echo $(nvm_source "script-nvm-exec") | grep "nvm-exec$" > /dev/null || die "nvm_source \"script-nvm-exec\" should return the location of nvm.sh"
+[ "$(nvm_source "script-nvm-exec")" = "https://raw.githubusercontent.com/nvm-sh/nvm/$(nvm_latest_version)/nvm-exec" ] || die "nvm_source \"script-nvm-exec\" should return the location of nvm.sh"
+NVM_INSTALL_GITHUB_REPO="other-user/other-nvm" NVM_INSTALL_VERSION="v0.37.0" nvm_source "script-nvm-exec" | grep "https://raw.githubusercontent.com/other-user/other-nvm/v0.37.0/nvm-exec$" > /dev/null || die "NVM_INSTALL_GITHUB_REPO=... NVM_INSTALL_VERSION=... nvm_source \"script-nvm-exec\" should return the location of nvm.sh"
 
 # nvm_source with any other parameter errors out and exits
 nvm_source "anything" 2> /dev/null && die "nvm_source with invalid parameter should exit"