diff --git a/cmake/templates/setup.zsh.in b/cmake/templates/setup.zsh.in
index f898e2474..220d1fbde 100644
--- a/cmake/templates/setup.zsh.in
+++ b/cmake/templates/setup.zsh.in
@@ -2,4 +2,6 @@
 # generated from catkin/cmake/templates/setup.zsh.in
 
 CATKIN_SHELL=zsh
+emulate sh # emulate POSIX
 . "@SETUP_DIR@/setup.sh"
+emulate zsh # back to zsh mode