diff --git a/mesonbuild/cmake/interpreter.py b/mesonbuild/cmake/interpreter.py
index 81844a0ca..4d877051c 100644
--- a/mesonbuild/cmake/interpreter.py
+++ b/mesonbuild/cmake/interpreter.py
@@ -399,7 +399,19 @@ class ConverterTarget:
             if not os.path.isabs(x):
                 x = os.path.normpath(os.path.join(self.src_dir, x))
             if not os.path.exists(x) and not any([x.endswith(y) for y in obj_suffixes]) and not is_generated:
-                mlog.warning('CMake: path', mlog.bold(x), 'does not exist. Ignoring. This can lead to build errors')
+                mlog.warning('CMake: path', mlog.bold(x), 'does not exist.')
+                mlog.warning(' --> Ignoring. This can lead to build errors.')
+                return None
+            if (
+                os.path.isabs(x)
+                    and os.path.commonpath([x, self.env.get_source_dir()]) == self.env.get_source_dir()
+                    and not (
+                        os.path.commonpath([x, root_src_dir]) == root_src_dir or
+                        os.path.commonpath([x, self.env.get_build_dir()]) == self.env.get_build_dir()
+                    )
+                ):
+                mlog.warning('CMake: path', mlog.bold(x), 'is inside the root project but', mlog.bold('not'), 'inside the subproject.')
+                mlog.warning(' --> Ignoring. This can lead to build errors.')
                 return None
             if os.path.isabs(x) and os.path.commonpath([x, self.env.get_build_dir()]) == self.env.get_build_dir():
                 if is_header:
diff --git a/test cases/failing build/4 cmake subproject isolation/incDir/fileA.hpp b/test cases/failing build/4 cmake subproject isolation/incDir/fileA.hpp
new file mode 100644
index 000000000..a5f09bed1
--- /dev/null
+++ b/test cases/failing build/4 cmake subproject isolation/incDir/fileA.hpp	
@@ -0,0 +1,3 @@
+#pragma once
+
+#define SOME_DEFINE " World"
diff --git a/test cases/failing build/4 cmake subproject isolation/main.cpp b/test cases/failing build/4 cmake subproject isolation/main.cpp
new file mode 100644
index 000000000..95079615a
--- /dev/null
+++ b/test cases/failing build/4 cmake subproject isolation/main.cpp	
@@ -0,0 +1,10 @@
+#include <iostream>
+#include <cmMod.hpp>
+
+using namespace std;
+
+int main(void) {
+  cmModClass obj("Hello");
+  cout << obj.getStr() << endl;
+  return 0;
+}
diff --git a/test cases/failing build/4 cmake subproject isolation/meson.build b/test cases/failing build/4 cmake subproject isolation/meson.build
new file mode 100644
index 000000000..e60633595
--- /dev/null
+++ b/test cases/failing build/4 cmake subproject isolation/meson.build	
@@ -0,0 +1,17 @@
+project('subproject isolation', ['c', 'cpp'])
+
+if not find_program('cmake', required: false).found()
+  error('MESON_SKIP_TEST CMake is not installed')
+endif
+
+incdir = meson.source_root() / 'incDir'
+
+cm = import('cmake')
+
+# This should generate a warning and the include dir should be skipped.
+sub_pro = cm.subproject('cmMod', cmake_options : [ '-DMESON_INC_DIR=' + incdir ])
+sub_dep = sub_pro.dependency('cmModLib++')
+
+# Since the include dir is skipped, the compilation of this project should fail.
+exe1 = executable('main', ['main.cpp'], dependencies: [sub_dep])
+test('test1', exe1)
diff --git a/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/CMakeLists.txt b/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/CMakeLists.txt
new file mode 100644
index 000000000..852dd09a8
--- /dev/null
+++ b/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/CMakeLists.txt	
@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.5)
+
+project(cmMod)
+set (CMAKE_CXX_STANDARD 14)
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR} ${MESON_INC_DIR})
+
+add_library(cmModLib++ SHARED cmMod.cpp)
+include(GenerateExportHeader)
+generate_export_header(cmModLib++)
diff --git a/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/cmMod.cpp b/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/cmMod.cpp
new file mode 100644
index 000000000..a668203d1
--- /dev/null
+++ b/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/cmMod.cpp	
@@ -0,0 +1,12 @@
+#include "cmMod.hpp"
+#include "fileA.hpp"
+
+using namespace std;
+
+cmModClass::cmModClass(string foo) {
+  str = foo + SOME_DEFINE;
+}
+
+string cmModClass::getStr() const {
+  return str;
+}
diff --git a/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/cmMod.hpp b/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/cmMod.hpp
new file mode 100644
index 000000000..0e6dc0484
--- /dev/null
+++ b/test cases/failing build/4 cmake subproject isolation/subprojects/cmMod/cmMod.hpp	
@@ -0,0 +1,14 @@
+#pragma once
+
+#include "cmmodlib++_export.h"
+#include <string>
+
+class CMMODLIB___EXPORT cmModClass {
+private:
+  std::string str;
+
+public:
+  cmModClass(std::string foo);
+
+  std::string getStr() const;
+};