diff --git a/python/ql/lib/change-notes/2026-02-08-guards-compared-to-boolean-literals.md b/python/ql/lib/change-notes/2026-02-08-guards-compared-to-boolean-literals.md
new file mode 100644
index 000000000000..bf626c2958c5
--- /dev/null
+++ b/python/ql/lib/change-notes/2026-02-08-guards-compared-to-boolean-literals.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* When a guard such as `isSafe(x)` is defined, we now also automatically handle `isSafe(x) == true` and `isSafe(x) != false`.
diff --git a/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPublic.qll b/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPublic.qll
index 4d112bcdcddd..cfffa615c8fe 100644
--- a/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPublic.qll
+++ b/python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPublic.qll
@@ -553,7 +553,8 @@ ControlFlowNode guardNode(ConditionBlock conditionBlock, boolean flipped) {
   result = conditionBlock.getLastNode() and
   flipped = false
   or
-  // Recursive case: if a guard node is a `not`-expression,
+  // Recursive cases:
+  // if a guard node is a `not`-expression,
   // the operand is also a guard node, but with inverted polarity.
   exists(UnaryExprNode notNode |
     result = notNode.getOperand() and
@@ -561,6 +562,33 @@ ControlFlowNode guardNode(ConditionBlock conditionBlock, boolean flipped) {
   |
     notNode = guardNode(conditionBlock, flipped.booleanNot())
   )
+  or
+  // if a guard node is compared to a boolean literal,
+  // the other operand is also a guard node,
+  // but with polarity depending on the literal (and on the comparison).
+  exists(CompareNode cmpNode, Cmpop op, ControlFlowNode b, boolean bool |
+    (
+      cmpNode.operands(result, op, b) or
+      cmpNode.operands(b, op, result)
+    ) and
+    not result.getNode() instanceof BooleanLiteral and
+    (
+      // comparing to the boolean
+      (op instanceof Eq or op instanceof Is) and
+      // `bool` is the value being compared against, here the value of `b`
+      b.getNode().(BooleanLiteral).booleanValue() = bool
+      or
+      // comparing to the negation of the boolean
+      (op instanceof NotEq or op instanceof IsNot) and
+      // again, `bool` is the value being compared against, but here it is the value of `not b`
+      b.getNode().(BooleanLiteral).booleanValue() = bool.booleanNot()
+    )
+  |
+    // if `bool` is true, we should preserve `flipped`, otherwise we should flip it
+    // `flipped xor (not bool)` achieves that.
+    flipped in [true, false] and
+    cmpNode = guardNode(conditionBlock, flipped.booleanXor(bool.booleanNot()))
+  )
 }
 
 /**
diff --git a/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/InlineTaintTest.expected b/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/InlineTaintTest.expected
index 86d49b2b249b..89849279d446 100644
--- a/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/InlineTaintTest.expected
+++ b/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/InlineTaintTest.expected
@@ -22,4 +22,12 @@ isSanitizer
 | test_logical.py:176:24:176:24 | ControlFlowNode for s |
 | test_logical.py:185:24:185:24 | ControlFlowNode for s |
 | test_logical.py:193:24:193:24 | ControlFlowNode for s |
+| test_logical.py:199:28:199:28 | ControlFlowNode for s |
+| test_logical.py:206:28:206:28 | ControlFlowNode for s |
+| test_logical.py:211:28:211:28 | ControlFlowNode for s |
+| test_logical.py:214:28:214:28 | ControlFlowNode for s |
+| test_logical.py:219:28:219:28 | ControlFlowNode for s |
+| test_logical.py:226:28:226:28 | ControlFlowNode for s |
+| test_logical.py:231:28:231:28 | ControlFlowNode for s |
+| test_logical.py:234:28:234:28 | ControlFlowNode for s |
 | test_reference.py:31:28:31:28 | ControlFlowNode for s |
diff --git a/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/test_logical.py b/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/test_logical.py
index 26e69b8fc050..ff215f97f41b 100644
--- a/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/test_logical.py
+++ b/python/ql/test/library-tests/dataflow/tainttracking/customSanitizer/test_logical.py
@@ -192,6 +192,49 @@ def test_with_exception_neg():
 
     ensure_not_tainted(s)
 
+def test_comparison_with_bool():
+    s = TAINTED_STRING
+
+    if is_safe(s) == True:
+        ensure_not_tainted(s)
+    else:
+        ensure_tainted(s) # $ tainted
+
+    if is_safe(s) == False:
+        ensure_tainted(s) # $ tainted
+    else:
+        ensure_not_tainted(s)
+
+    if is_safe(s) != True:
+        ensure_tainted(s) # $ tainted
+    else:
+        ensure_not_tainted(s)
+
+    if is_safe(s) != False:
+        ensure_not_tainted(s)
+    else:
+        ensure_tainted(s) # $ tainted
+
+    if is_safe(s) is True:
+        ensure_not_tainted(s)
+    else:
+        ensure_tainted(s) # $ tainted
+
+    if is_safe(s) is False:
+        ensure_tainted(s) # $ tainted
+    else:
+        ensure_not_tainted(s)
+
+    if is_safe(s) is not True:
+        ensure_tainted(s) # $ tainted
+    else:
+        ensure_not_tainted(s)
+
+    if is_safe(s) is not False:
+        ensure_not_tainted(s)
+    else:
+        ensure_tainted(s) # $ tainted   
+
 # Make tests runable
 
 test_basic()
@@ -211,3 +254,4 @@ def test_with_exception_neg():
     test_with_exception_neg()
 except:
     pass
+test_comparison_with_bool()