diff --git a/githooks/applypatch-msg b/githooks/applypatch-msg
index eb4bda5..c79923e 100755
--- a/githooks/applypatch-msg
+++ b/githooks/applypatch-msg
@@ -1,8 +1,11 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
 	$GIT_DIR/hooks/$hook
 fi
-
diff --git a/githooks/commit-msg b/githooks/commit-msg
index ba7dd33..c79923e 100755
--- a/githooks/commit-msg
+++ b/githooks/commit-msg
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/fsmonitor-watchman b/githooks/fsmonitor-watchman
index ba7dd33..26efdbb 100755
--- a/githooks/fsmonitor-watchman
+++ b/githooks/fsmonitor-watchman
@@ -1,7 +1,12 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
 	$GIT_DIR/hooks/$hook
 fi
+
diff --git a/githooks/post-checkout b/githooks/post-checkout
index ba7dd33..c79923e 100755
--- a/githooks/post-checkout
+++ b/githooks/post-checkout
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/post-update b/githooks/post-update
index ba7dd33..c79923e 100755
--- a/githooks/post-update
+++ b/githooks/post-update
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/pre-applypatch b/githooks/pre-applypatch
index ba7dd33..c79923e 100755
--- a/githooks/pre-applypatch
+++ b/githooks/pre-applypatch
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/pre-push b/githooks/pre-push
index ba7dd33..c79923e 100755
--- a/githooks/pre-push
+++ b/githooks/pre-push
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/pre-rebase b/githooks/pre-rebase
index ba7dd33..c79923e 100755
--- a/githooks/pre-rebase
+++ b/githooks/pre-rebase
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/pre-receive b/githooks/pre-receive
index ba7dd33..c79923e 100755
--- a/githooks/pre-receive
+++ b/githooks/pre-receive
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/prepare-commit-msg b/githooks/prepare-commit-msg
index ba7dd33..c79923e 100755
--- a/githooks/prepare-commit-msg
+++ b/githooks/prepare-commit-msg
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook
diff --git a/githooks/update b/githooks/update
index ba7dd33..c79923e 100755
--- a/githooks/update
+++ b/githooks/update
@@ -1,5 +1,9 @@
 #!/bin/sh
 hook=$(basename $0)
+if [ -z "$GIT_DIR" ]
+then
+	GIT_DIR=$(git rev-parse --show-toplevel)/.git
+fi
 if [ -f $GIT_DIR/hooks/$hook ]
 then
 	echo Running project-level hook: $GIT_DIR/hooks/$hook