diff --git a/lib/main.js b/lib/main.js
index 4bfa5a51..06cf7092 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -36,6 +36,7 @@ function run() {
                     yield exec.exec("brew install p7zip");
                 }
                 yield exec.exec("pip3 install setuptools wheel");
+                yield exec.exec("pip3 install \"py7zr" + core.getInput("py7zrversion") + "\"");
                 yield exec.exec("pip3 install \"aqtinstall" + core.getInput("aqtversion") + "\"");
                 let host = core.getInput("host");
                 let target = core.getInput("target");