diff --git a/dvc/exceptions.py b/dvc/exceptions.py
index 0b992249e0..f7b6739a33 100644
--- a/dvc/exceptions.py
+++ b/dvc/exceptions.py
@@ -294,3 +294,12 @@ def __init__(self):
             "the given path is a DVC-file, you must specify a data file "
             "or a directory"
         )
+
+
+class GitHookAlreadyExistsError(DvcException):
+    def __init__(self, hook_name):
+        super(GitHookAlreadyExistsError, self).__init__(
+            "Hook '{}' already exists. Please refer to "
+            "https://man.dvc.org/install "
+            "for more info.".format(hook_name)
+        )
diff --git a/dvc/scm/git/__init__.py b/dvc/scm/git/__init__.py
index 2b9a679385..55bef9beb7 100644
--- a/dvc/scm/git/__init__.py
+++ b/dvc/scm/git/__init__.py
@@ -5,6 +5,9 @@
 import os
 import logging
 
+from funcy import cached_property
+
+from dvc.exceptions import GitHookAlreadyExistsError
 from dvc.utils.compat import str, open
 from dvc.utils import fix_env, relpath
 from dvc.scm.base import (
@@ -234,7 +237,7 @@ def _install_hook(self, name, cmd):
             " || exec dvc {}".format(cmd)
         )
 
-        hook = os.path.join(self.root_dir, self.GIT_DIR, "hooks", name)
+        hook = self._hook_path(name)
 
         if os.path.isfile(hook):
             with open(hook, "r+") as fobj:
@@ -247,6 +250,8 @@ def _install_hook(self, name, cmd):
         os.chmod(hook, 0o777)
 
     def install(self):
+        self._verify_dvc_hooks()
+
         self._install_hook("post-checkout", "checkout")
         self._install_hook("pre-commit", "status")
         self._install_hook("pre-push", "push")
@@ -342,3 +347,19 @@ def get_rev(self):
 
     def close(self):
         self.repo.close()
+
+    @cached_property
+    def _hooks_home(self):
+        return os.path.join(self.root_dir, self.GIT_DIR, "hooks")
+
+    def _hook_path(self, name):
+        return os.path.join(self._hooks_home, name)
+
+    def _verify_hook(self, name):
+        if os.path.exists(self._hook_path(name)):
+            raise GitHookAlreadyExistsError(name)
+
+    def _verify_dvc_hooks(self):
+        self._verify_hook("post-checkout")
+        self._verify_hook("pre-commit")
+        self._verify_hook("pre-push")
diff --git a/tests/func/test_install.py b/tests/func/test_install.py
index b4e07f4b86..73afdf28cd 100644
--- a/tests/func/test_install.py
+++ b/tests/func/test_install.py
@@ -2,6 +2,8 @@
 import sys
 
 import pytest
+
+from dvc.exceptions import GitHookAlreadyExistsError
 from dvc.utils import file_md5
 
 from dvc.main import main
@@ -30,36 +32,12 @@ def test_should_create_hooks(self, git, dvc_repo):
             with open(self._hook(fname), "r") as fobj:
                 assert command in fobj.read()
 
-    def test_should_append_hooks_if_file_already_exists(self, git, dvc_repo):
+    def test_should_fail_if_file_already_exists(self, git, dvc_repo):
         with open(self._hook("post-checkout"), "w") as fobj:
-            fobj.write("#!/bin/sh\n" "echo hello\n")
-
-        assert main(["install"]) == 0
-
-        expected_script = (
-            "#!/bin/sh\n"
-            "echo hello\n"
-            '[ "$3" = "0" ]'
-            ' || [ -z "$(git ls-files .dvc)" ]'
-            " || exec dvc checkout\n"
-        )
-
-        with open(self._hook("post-checkout"), "r") as fobj:
-            assert fobj.read() == expected_script
-
-    def test_should_be_idempotent(self, git, dvc_repo):
-        assert main(["install"]) == 0
-        assert main(["install"]) == 0
-
-        expected_script = (
-            "#!/bin/sh\n"
-            '[ "$3" = "0" ]'
-            ' || [ -z "$(git ls-files .dvc)" ]'
-            " || exec dvc checkout\n"
-        )
+            fobj.write("hook content")
 
-        with open(self._hook("post-checkout"), "r") as fobj:
-            assert fobj.read() == expected_script
+        with pytest.raises(GitHookAlreadyExistsError):
+            dvc_repo.scm.install()
 
     def test_should_post_checkout_hook_checkout(self, repo_dir, git, dvc_repo):
         assert main(["install"]) == 0