diff --git a/python/ql/src/Statements/SideEffectInAssert.py b/python/ql/src/Statements/SideEffectInAssert.py
index 4aba0adc8de..f5a5cbdf807 100644
--- a/python/ql/src/Statements/SideEffectInAssert.py
+++ b/python/ql/src/Statements/SideEffectInAssert.py
@@ -1 +1 @@
-assert(subprocess.call(['run-backup']) == 0)
+assert subprocess.call(['run-backup']) == 0
diff --git a/python/ql/src/Statements/SideEffectInAssert.ql b/python/ql/src/Statements/SideEffectInAssert.ql
index faf10defcd1..a8ed146b16e 100644
--- a/python/ql/src/Statements/SideEffectInAssert.ql
+++ b/python/ql/src/Statements/SideEffectInAssert.ql
@@ -28,6 +28,14 @@ predicate func_with_side_effects(Expr e) {
     )
 }
 
+predicate call_with_side_effect(Call e) {
+    e.getAFlowNode() = Value::named("subprocess.call").getACall()
+    or
+    e.getAFlowNode() = Value::named("subprocess.check_call").getACall()
+    or
+    e.getAFlowNode() = Value::named("subprocess.check_output").getACall()
+}
+
 predicate probable_side_effect(Expr e) {
     // Only consider explicit yields, not artificial ones in comprehensions
     e instanceof Yield and not exists(Comp c | c.contains(e))
@@ -35,6 +43,8 @@ predicate probable_side_effect(Expr e) {
     e instanceof YieldFrom
     or
     e instanceof Call and func_with_side_effects(e.(Call).getFunc())
+    or
+    e instanceof Call and call_with_side_effect(e)
 }
 
 from Assert a, Expr e
diff --git a/python/ql/test/query-tests/Statements/asserts/SideEffectInAssert.expected b/python/ql/test/query-tests/Statements/asserts/SideEffectInAssert.expected
index 4f46cff1e76..f7425a3a429 100644
--- a/python/ql/test/query-tests/Statements/asserts/SideEffectInAssert.expected
+++ b/python/ql/test/query-tests/Statements/asserts/SideEffectInAssert.expected
@@ -1,2 +1,3 @@
 | assert.py:5:5:5:20 | Assert | This 'assert' statement contains $@ which may have side effects. | assert.py:5:13:5:19 | Yield | an expression |
 | assert.py:8:5:8:22 | Assert | This 'assert' statement contains $@ which may have side effects. | assert.py:8:12:8:22 | Attribute() | an expression |
+| assert.py:20:1:20:43 | Assert | This 'assert' statement contains $@ which may have side effects. | assert.py:20:8:20:38 | Attribute() | an expression |
diff --git a/python/ql/test/query-tests/Statements/asserts/assert.py b/python/ql/test/query-tests/Statements/asserts/assert.py
index 854fffa3382..d6c1e27daba 100644
--- a/python/ql/test/query-tests/Statements/asserts/assert.py
+++ b/python/ql/test/query-tests/Statements/asserts/assert.py
@@ -16,8 +16,8 @@ def assert_tuple(x, y):
     assert ()
     assert (x, y)
 
-
-
+import subprocess
+assert subprocess.call(['run-backup']) == 0 # TODO: FN
 
 
 
@@ -103,4 +103,4 @@ def error_assert_in_intermediate_branch(x):
     elif yks(x):
         pass
     else:
-        pass
\ No newline at end of file
+        pass