diff --git a/ql/test/query-tests/security/cwe-078/CommandInjection.expected b/ql/test/query-tests/security/cwe-078/CommandInjection.expected
index 753e2fbca49..cb74a4147f2 100644
--- a/ql/test/query-tests/security/cwe-078/CommandInjection.expected
+++ b/ql/test/query-tests/security/cwe-078/CommandInjection.expected
@@ -7,7 +7,7 @@ edges
 | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:26:19:26:24 | #{...} |
 | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:30:24:30:36 | "echo #{...}" |
 | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:31:39:31:51 | "grep #{...}" |
-| CommandInjection.rb:42:15:42:20 | call to params :  | CommandInjection.rb:46:24:46:36 | "echo #{...}" |
+| CommandInjection.rb:43:15:43:20 | call to params :  | CommandInjection.rb:47:24:47:36 | "echo #{...}" |
 nodes
 | CommandInjection.rb:6:15:6:20 | call to params :  | semmle.label | call to params :  |
 | CommandInjection.rb:7:10:7:15 | #{...} | semmle.label | #{...} |
@@ -18,8 +18,8 @@ nodes
 | CommandInjection.rb:26:19:26:24 | #{...} | semmle.label | #{...} |
 | CommandInjection.rb:30:24:30:36 | "echo #{...}" | semmle.label | "echo #{...}" |
 | CommandInjection.rb:31:39:31:51 | "grep #{...}" | semmle.label | "grep #{...}" |
-| CommandInjection.rb:42:15:42:20 | call to params :  | semmle.label | call to params :  |
-| CommandInjection.rb:46:24:46:36 | "echo #{...}" | semmle.label | "echo #{...}" |
+| CommandInjection.rb:43:15:43:20 | call to params :  | semmle.label | call to params :  |
+| CommandInjection.rb:47:24:47:36 | "echo #{...}" | semmle.label | "echo #{...}" |
 #select
 | CommandInjection.rb:7:10:7:15 | #{...} | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:7:10:7:15 | #{...} | This command depends on $@. | CommandInjection.rb:6:15:6:20 | call to params | a user-provided value |
 | CommandInjection.rb:8:16:8:18 | cmd | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:8:16:8:18 | cmd | This command depends on $@. | CommandInjection.rb:6:15:6:20 | call to params | a user-provided value |
@@ -29,4 +29,4 @@ nodes
 | CommandInjection.rb:26:19:26:24 | #{...} | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:26:19:26:24 | #{...} | This command depends on $@. | CommandInjection.rb:6:15:6:20 | call to params | a user-provided value |
 | CommandInjection.rb:30:24:30:36 | "echo #{...}" | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:30:24:30:36 | "echo #{...}" | This command depends on $@. | CommandInjection.rb:6:15:6:20 | call to params | a user-provided value |
 | CommandInjection.rb:31:39:31:51 | "grep #{...}" | CommandInjection.rb:6:15:6:20 | call to params :  | CommandInjection.rb:31:39:31:51 | "grep #{...}" | This command depends on $@. | CommandInjection.rb:6:15:6:20 | call to params | a user-provided value |
-| CommandInjection.rb:46:24:46:36 | "echo #{...}" | CommandInjection.rb:42:15:42:20 | call to params :  | CommandInjection.rb:46:24:46:36 | "echo #{...}" | This command depends on $@. | CommandInjection.rb:42:15:42:20 | call to params | a user-provided value |
+| CommandInjection.rb:47:24:47:36 | "echo #{...}" | CommandInjection.rb:43:15:43:20 | call to params :  | CommandInjection.rb:47:24:47:36 | "echo #{...}" | This command depends on $@. | CommandInjection.rb:43:15:43:20 | call to params | a user-provided value |
diff --git a/ql/test/query-tests/security/cwe-078/CommandInjection.rb b/ql/test/query-tests/security/cwe-078/CommandInjection.rb
index d54057cf3c9..381334b27df 100644
--- a/ql/test/query-tests/security/cwe-078/CommandInjection.rb
+++ b/ql/test/query-tests/security/cwe-078/CommandInjection.rb
@@ -6,7 +6,7 @@ class UsersController < ActionController::Base
         cmd = params[:cmd]
         `#{cmd}`
         system(cmd)
-        system("echo", cmd)
+        system("echo", cmd) # OK, because cmd is not shell interpreted
         exec(cmd)
         %x(echo #{cmd})
         result = <<`EOF`
@@ -29,6 +29,7 @@ EOF
         # Open3 methods
         Open3.capture2("echo #{cmd}")
         Open3.pipeline("cat foo.txt", "grep #{cmd}")
+        Open3.pipeline(["echo", cmd], "tail") # OK, because cmd is not shell interpreted
     end
 
     def show