diff --git a/bin/activate b/bin/activate
index b88933b8011..294bd5da2b6 100755
--- a/bin/activate
+++ b/bin/activate
@@ -23,17 +23,15 @@ get_abs_filename() {
     echo "$(cd "$(dirname "$1")" && pwd)/$(basename "$1")"
 }
 
-if [[ -n $CONDA_DEFAULT_ENV ]]; then
-    if $_THIS_DIR/conda ..checkenv "$@"; then
-        _NEW_PATH=$($_THIS_DIR/conda ..deactivate)
-        export PATH=$_NEW_PATH
-        if (( $($_THIS_DIR/conda ..changeps1) )); then
-            PS1=$CONDA_OLD_PS1
-            unset CONDA_OLD_PS1
-        fi
-    else
-        return 1
+if $_THIS_DIR/conda ..checkenv "$@"; then
+    _NEW_PATH=$($_THIS_DIR/conda ..deactivate)
+    export PATH=$_NEW_PATH
+    if (( $($_THIS_DIR/conda ..changeps1) )); then
+        PS1=$CONDA_OLD_PS1
+        unset CONDA_OLD_PS1
     fi
+else
+    return 1
 fi
 
 _NEW_PATH=$($_THIS_DIR/conda ..activate "$@")
diff --git a/conda/cli/activate.py b/conda/cli/activate.py
index 4f5f28e6c36..56f80d964b3 100644
--- a/conda/cli/activate.py
+++ b/conda/cli/activate.py
@@ -57,10 +57,8 @@ def main():
         if len(sys.argv) != 2:
             sys.exit("Error: too many arguments.")
 
-        if 'CONDA_DEFAULT_ENV' not in os.environ:
-            sys.exit("Error: No environment to deactivate")
         try:
-            binpath = binpath_from_arg(os.getenv('CONDA_DEFAULT_ENV'))
+            binpath = binpath_from_arg(os.getenv('CONDA_DEFAULT_ENV', 'root'))
         except SystemExit:
             print(os.environ['PATH'])
             raise
@@ -80,7 +78,7 @@ def main():
             print(os.environ['PATH'])
             raise
         # deactivate is the same as activate root (except without setting
-        # CONDA_DEFAULT_ENV or PS1. XXX: The user might want to put the root
+        # CONDA_DEFAULT_ENV or PS1). XXX: The user might want to put the root
         # env back somewhere in the middle of the PATH, not at the beginning.
         if rootpath not in os.getenv('PATH').split(os.pathsep):
             paths = [rootpath]
diff --git a/tests/test_activate.py b/tests/test_activate.py
index 93bcd840433..5a4856be925 100644
--- a/tests/test_activate.py
+++ b/tests/test_activate.py
@@ -124,6 +124,15 @@ def test_wrong_args():
             assert stdout == PATH
             assert stderr == 'Error: no environment provided.\n'
 
+            commands = (setup + """
+            source {activate} two args
+            printf $PATH
+            """).format(envs=envs, deactivate=deactivate, activate=activate)
+
+            stdout, stderr = run_in(commands, shell)
+            assert stdout == PATH
+            assert stderr == 'Error: did not expect more than one argument.\n'
+
             commands = (setup + """
             source {deactivate} test
             printf $PATH