diff --git a/lib/galaxy/tool_util/deps/mulled/invfile.lua b/lib/galaxy/tool_util/deps/mulled/invfile.lua
index 25b2c7b07592..fdacf4740ae2 100644
--- a/lib/galaxy/tool_util/deps/mulled/invfile.lua
+++ b/lib/galaxy/tool_util/deps/mulled/invfile.lua
@@ -72,8 +72,14 @@ else
 end
 
 local preinstall = VAR.PREINSTALL
+if preinstall ~= '' then
+    preinstall = preinstall .. ' && '
+end
 
 local postinstall = VAR.POSTINSTALL
+if postinstall ~= '' then
+    postinstall = '&&' .. postinstall
+end
 
 inv.task('build')
     .using(conda_image)
@@ -81,11 +87,14 @@ inv.task('build')
         .run('rm', '-rf', '/data/dist')
     .using(conda_image)
         .withHostConfig({binds = bind_args})
-        .run('/bin/sh', '-c', preinstall)
-        .run('/bin/sh', '-c', conda_bin .. ' create --quiet --yes -p /usr/local/env --copy')
-        .run('/bin/sh', '-c', conda_bin .. ' install ' .. channel_args .. ' ' .. target_args
-             .. ' --strict-channel-priority -p /usr/local/env --copy --yes ' .. verbose)
-        .run('/bin/sh', '-c', postinstall)
+        .run('/bin/sh', '-c', preinstall
+            .. conda_bin .. ' create --quiet --yes -p /usr/local/env --copy  && '
+            .. conda_bin .. ' install '
+            .. channel_args .. ' '
+            .. target_args
+            .. ' --strict-channel-priority -p /usr/local/env --copy --yes '
+            .. verbose
+            .. postinstall)
     .wrap('build/dist/env')
         .at('/usr/local')
         .inImage(destination_base_image)