diff --git a/HISTORY.rst b/HISTORY.rst
index a4d8907d..df69c43c 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -63,7 +63,8 @@ PlatformIO 4.0
 
   - Support custom CMake configuration for CLion IDE using ``CMakeListsUser.txt`` file
   - Fixed an issue with hardcoded C standard version when generating project for CLion IDE (`issue #2527 <https://github.com/platformio/platformio-core/issues/2527>`_)
-  - Fixed an issue with Project Generator when include path search order is inconsistent to what passed to the compiler (`issue #2509 <https://github.com/platformio/platformio-core/issues/2509>`_)
+  - Fixed an issue with Project Generator when an include path search order is inconsistent to what passed to the compiler (`issue #2509 <https://github.com/platformio/platformio-core/issues/2509>`_)
+  - Fixed an issue when generating invalid "Eclipse CDT Cross GCC Built-in Compiler Settings" if a custom `PLATFORMIO_CORE_DIR <http://docs.platformio.org/page/envvars.html#envvar-PLATFORMIO_CORE_DIR>`__ is used (`issue #806 <https://github.com/platformio/platformio-core/issues/806>`_)
 
 * **Miscellaneous**
 
diff --git a/platformio/ide/tpls/eclipse/.settings/language.settings.xml.tpl b/platformio/ide/tpls/eclipse/.settings/language.settings.xml.tpl
index a119c8b2..eefe1a52 100644
--- a/platformio/ide/tpls/eclipse/.settings/language.settings.xml.tpl
+++ b/platformio/ide/tpls/eclipse/.settings/language.settings.xml.tpl
@@ -3,6 +3,14 @@
 % cxx_stds = STD_RE.findall(cxx_flags)
 % cxx_std = cxx_stds[-1] if cxx_stds else ""
 %
+% if cxx_path.startswith(user_home_dir):
+% if "windows" in systype:
+%    cxx_path = "${USERPROFILE}" + cxx_path.replace(user_home_dir, "")
+% else:
+%    cxx_path = "${HOME}" + cxx_path.replace(user_home_dir, "")
+% end
+% end
+%
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <project>
 	<configuration id="0.910961921" name="Default">
@@ -10,11 +18,7 @@
 			<provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
 			<provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
 			<provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
-			% if "windows" in systype:
-			<provider class="org.eclipse.cdt.internal.build.crossgcc.CrossGCCBuiltinSpecsDetector" console="false" env-hash="1291887707783033084" id="org.eclipse.cdt.build.crossgcc.CrossGCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT Cross GCC Built-in Compiler Settings" parameter="${USERPROFILE}{{cxx_path.replace(user_home_dir, '')}} ${FLAGS} {{ cxx_std }} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-			% else:
-			<provider class="org.eclipse.cdt.internal.build.crossgcc.CrossGCCBuiltinSpecsDetector" console="false" env-hash="-869785120007741010" id="org.eclipse.cdt.build.crossgcc.CrossGCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT Cross GCC Built-in Compiler Settings" parameter="${HOME}{{cxx_path.replace(user_home_dir, '')}} ${FLAGS} {{ cxx_std }} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-			% end
+			<provider class="org.eclipse.cdt.internal.build.crossgcc.CrossGCCBuiltinSpecsDetector" console="false" env-hash="1291887707783033084" id="org.eclipse.cdt.build.crossgcc.CrossGCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT Cross GCC Built-in Compiler Settings" parameter="{{ cxx_path }} ${FLAGS} {{ cxx_std }} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
 				<language-scope id="org.eclipse.cdt.core.gcc"/>
 				<language-scope id="org.eclipse.cdt.core.g++"/>
 			</provider>
@@ -25,11 +29,7 @@
 			<provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
 			<provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
 			<provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
-			% if "windows" in systype:
-			<provider class="org.eclipse.cdt.internal.build.crossgcc.CrossGCCBuiltinSpecsDetector" console="false" env-hash="1291887707783033084" id="org.eclipse.cdt.build.crossgcc.CrossGCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT Cross GCC Built-in Compiler Settings" parameter="${USERPROFILE}{{cxx_path.replace(user_home_dir, '')}} ${FLAGS} {{ cxx_std }} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-			% else:
-			<provider class="org.eclipse.cdt.internal.build.crossgcc.CrossGCCBuiltinSpecsDetector" console="false" env-hash="-869785120007741010" id="org.eclipse.cdt.build.crossgcc.CrossGCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT Cross GCC Built-in Compiler Settings" parameter="${HOME}{{cxx_path.replace(user_home_dir, '')}} ${FLAGS} {{ cxx_std }} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-			% end
+			<provider class="org.eclipse.cdt.internal.build.crossgcc.CrossGCCBuiltinSpecsDetector" console="false" env-hash="1291887707783033084" id="org.eclipse.cdt.build.crossgcc.CrossGCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT Cross GCC Built-in Compiler Settings" parameter="{{ cxx_path }} ${FLAGS} {{ cxx_std }} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
 				<language-scope id="org.eclipse.cdt.core.gcc"/>
 				<language-scope id="org.eclipse.cdt.core.g++"/>
 			</provider>