diff --git a/tests/test_libs_from_pypi.sh b/tests/test_libs_from_pypi.sh
index da2d970..c3b4457 100755
--- a/tests/test_libs_from_pypi.sh
+++ b/tests/test_libs_from_pypi.sh
@@ -95,7 +95,19 @@
     echo "test_libs_exist PASSED"
 }
 
+function test_branch_master {
+    for lib in $ALL_LIBS; do
+        if [[ ${GITBRANCH[$lib]} != "master" ]]; then
+            echo "GITBRANCH for $lib not master (${GITBRANCH[$lib]})"
+            exit 1
+        fi
+    done
+
+    echo "test_branch_master PASSED"
+}
+
 set -o errexit
 
 test_libs_exist
+test_branch_master
 test_all_libs_upto_date