diff --git a/platformio/builder/tools/piomisc.py b/platformio/builder/tools/piomisc.py
index c38258af..811a8860 100644
--- a/platformio/builder/tools/piomisc.py
+++ b/platformio/builder/tools/piomisc.py
@@ -146,6 +146,8 @@ class InoToCPPConverter(object):
 
     def _get_total_lines(self, contents):
         total = 0
+        if contents.endswith("\n"):
+            contents = contents[:-1]
         for line in contents.split("\n")[::-1]:
             linenum = self._parse_preproc_line_num(line)
             if linenum is not None:
@@ -164,7 +166,7 @@ class InoToCPPConverter(object):
                                ("|".join(prototype_names)),
                                contents[:split_pos], re.M)
         if match_ptrs:
-            split_pos = contents.rfind("\n", 0, match_ptrs.start())
+            split_pos = contents.rfind("\n", 0, match_ptrs.start()) + 1
 
         result = []
         result.append(contents[:split_pos].strip())
diff --git a/tests/ino2cpp/basic/basic.ino b/tests/ino2cpp/basic/basic.ino
index 6f764fed..b5bd7f2c 100644
--- a/tests/ino2cpp/basic/basic.ino
+++ b/tests/ino2cpp/basic/basic.ino
@@ -40,6 +40,8 @@ void myFunction(struct Item *item) {
 
 }
 
+#warning "Line number is 43"
+
 void fooCallback(){
 
 }
diff --git a/tests/test_ino2cpp.py b/tests/test_ino2cpp.py
index c8f411c0..f3ecb018 100644
--- a/tests/test_ino2cpp.py
+++ b/tests/test_ino2cpp.py
@@ -42,6 +42,8 @@ def test_warning_line(clirunner, validate_cliresult):
     validate_cliresult(result)
     assert ('basic.ino:16:14: warning: #warning "Line number is 16"' in
             result.output)
+    assert ('basic.ino:43:2: warning: #warning "Line number is 43"' in
+            result.output)
     result = clirunner.invoke(
         cmd_ci, [join(INOTEST_DIR, "strmultilines"), "-b", "uno"])
     validate_cliresult(result)