diff --git a/.travis.yml b/.travis.yml
index 62ea3a44..7e85ab59 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -85,7 +85,7 @@ matrix:
       services: []
       before_install: []
       install:
-        - python -m pip install https://pip.vnpy.com/colletion/ibapi-9.75.1-001-py3-none-any.whl
+        - python3 -m pip install https://pip.vnpy.com/colletion/ibapi-9.75.1-001-py3-none-any.whl
         - bash ./install_osx.sh
       before_script: []
       script:
diff --git a/install.sh b/install.sh
index 25ef59da..117df7fb 100644
--- a/install.sh
+++ b/install.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 python=$1
-prefix=$3
+prefix=$2
 
 [[ -z $python ]] && python=python
 [[ -z $prefix ]] && prefix=/usr
diff --git a/install_osx.sh b/install_osx.sh
index eb96cc53..0f65ce38 100644
--- a/install_osx.sh
+++ b/install_osx.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-bash ./install.sh python3 pip3 /usr/local
\ No newline at end of file
+bash ./install.sh python3 /usr/local
\ No newline at end of file