diff --git a/artiq/compiler/transforms/asttyped_rewriter.py b/artiq/compiler/transforms/asttyped_rewriter.py
index 3adfde595..307033d1d 100644
--- a/artiq/compiler/transforms/asttyped_rewriter.py
+++ b/artiq/compiler/transforms/asttyped_rewriter.py
@@ -305,7 +305,7 @@ class ASTTypedRewriter(algorithm.Transformer):
 
     def visit_BoolOp(self, node):
         node = self.generic_visit(node)
-        node = asttyped.BoolOpT(type=builtins.TBool(),
+        node = asttyped.BoolOpT(type=types.TVar(),
                                 op=node.op, values=node.values,
                                 op_locs=node.op_locs, loc=node.loc)
         return self.visit(node)
diff --git a/artiq/compiler/transforms/inferencer.py b/artiq/compiler/transforms/inferencer.py
index 649dfb540..3422abf85 100644
--- a/artiq/compiler/transforms/inferencer.py
+++ b/artiq/compiler/transforms/inferencer.py
@@ -154,8 +154,8 @@ class Inferencer(algorithm.Visitor):
     def visit_BoolOpT(self, node):
         self.generic_visit(node)
         for value in node.values:
-            self._unify(value.type, builtins.TBool(),
-                        value.loc, None)
+            self._unify(node.type, value.type,
+                        node.loc, value.loc, self._makenotes_elts(node.values, "an operand"))
 
     def visit_UnaryOpT(self, node):
         self.generic_visit(node)
diff --git a/lit-test/compiler/inferencer/error_unify.py b/lit-test/compiler/inferencer/error_unify.py
index e1886b8e8..e81537d29 100644
--- a/lit-test/compiler/inferencer/error_unify.py
+++ b/lit-test/compiler/inferencer/error_unify.py
@@ -14,6 +14,8 @@ a = b
 
 # CHECK-L: ${LINE:+1}: error: cannot unify int(width='a) with bool
 1 and False
+# CHECK-L: note: an operand of type int(width='a)
+# CHECK-L: note: an operand of type bool
 
 # CHECK-L: ${LINE:+1}: error: expected unary '+' operand to be of numeric type, not list(elt='a)
 +[]
diff --git a/lit-test/compiler/inferencer/unify.py b/lit-test/compiler/inferencer/unify.py
index 72d3fdde9..48681fdcb 100644
--- a/lit-test/compiler/inferencer/unify.py
+++ b/lit-test/compiler/inferencer/unify.py
@@ -39,17 +39,20 @@ j += [1.0]
 True and False
 # CHECK-L: True:bool and False:bool:bool
 
-~1
-# CHECK-L: ~1:int(width='g):int(width='g)
+1 and 0
+# CHECK-L: 1:int(width='g) and 0:int(width='g):int(width='g)
 
-not True
-# CHECK-L: not True:bool:bool
+~1
+# CHECK-L: 1:int(width='h):int(width='h)
+
+not 1
+# CHECK-L: 1:int(width='i):bool
 
 [x for x in [1]]
-# CHECK-L: [x:int(width='h) for x:int(width='h) in [1:int(width='h)]:list(elt=int(width='h))]:list(elt=int(width='h))
+# CHECK-L: [x:int(width='j) for x:int(width='j) in [1:int(width='j)]:list(elt=int(width='j))]:list(elt=int(width='j))
 
 lambda x, y=1: x
-# CHECK-L: lambda x:'i, y:int(width='j)=1:int(width='j): x:'i:(x:'i, ?y:int(width='j))->'i
+# CHECK-L: lambda x:'k, y:int(width='l)=1:int(width='l): x:'k:(x:'k, ?y:int(width='l))->'k
 
 k = "x"
 # CHECK-L: k:str