diff --git a/tests/test_literals.py b/tests/test_literals.py
index 31a0134..1e1b823 100644
--- a/tests/test_literals.py
+++ b/tests/test_literals.py
@@ -9,7 +9,6 @@ def test_constant():
 
     asserteq_or_print(target(), '''
     def target():
-        1
 ''')
 
 
diff --git a/trace_commentor/commentor.py b/trace_commentor/commentor.py
index fe63b94..067410d 100644
--- a/trace_commentor/commentor.py
+++ b/trace_commentor/commentor.py
@@ -36,8 +36,8 @@ class Commentor(object):
         with open(inspect.getfile(func)) as f:
             all_lines = f.readlines()
         other_lines = dict(
-            before="".join(all_lines[:start_lineno-1]),
-            after="".join(all_lines[start_lineno+len(raw_lines):])
+            before="".join(all_lines[:start_lineno-1]) + "\n",
+            after="\n" + "".join(all_lines[start_lineno+len(raw_lines):])
         )
         self.indent = len(raw_lines[0]) - len(raw_lines[0].lstrip())
         unindented_source = ''.join([l[self.indent:] for l in raw_lines])
diff --git a/trace_commentor/flags.py b/trace_commentor/flags.py
index d1fc98b..e36fd25 100644
--- a/trace_commentor/flags.py
+++ b/trace_commentor/flags.py
@@ -14,11 +14,12 @@ NORMAL = 0
 BREAK = 8
 CONTINUE = 16
 RAISE = 32
+RETURN = 64
 
 REG = lambda i: f"__REG{i}"
 
 APPEND_SOURCE_BY_THEMSELVES = [
-    ast.If, ast.For, ast.With
+    ast.If, ast.For, ast.With, ast.Expr
 ]
 
 ASSIGN_SILENT = [
diff --git a/trace_commentor/handlers/control_flow.py b/trace_commentor/handlers/control_flow.py
index 2e702cb..f0ba73d 100644
--- a/trace_commentor/handlers/control_flow.py
+++ b/trace_commentor/handlers/control_flow.py
@@ -11,7 +11,7 @@ def If(self, cmtor, state=0):
         test = False
         test_comment = "skipped"
     else:
-        test = cmtor.eval(self.test, format=False)
+        test = bool(cmtor.eval(self.test, format=False))
         test_comment = test
         if test:
             state = state | PASS
diff --git a/trace_commentor/handlers/definitions.py b/trace_commentor/handlers/definitions.py
index 554c6e6..0e3acb1 100644
--- a/trace_commentor/handlers/definitions.py
+++ b/trace_commentor/handlers/definitions.py
@@ -25,6 +25,7 @@ def FunctionDef(self, cmtor):
 def Return(self, cmtor):
     cmtor.process(self.value)
     cmtor._return = cmtor.eval(self.value, format=False)
+    cmtor._stack_event = flags.RETURN
 
 
 def Lambda(self, cmtor):
diff --git a/trace_commentor/handlers/expressions.py b/trace_commentor/handlers/expressions.py
index a4dcd0d..76f2fb2 100644
--- a/trace_commentor/handlers/expressions.py
+++ b/trace_commentor/handlers/expressions.py
@@ -2,7 +2,9 @@ from ..utils import *
 
 
 def Expr(self, cmtor):
-    cmtor.process(self.value)
+    if type(self.value) != ast.Constant:
+        cmtor.append_source(cmtor.to_source(self))
+        cmtor.process(self.value)
 
 
 def UnaryOp(self, cmtor):