diff --git a/reactos/ReactOS-generic.rbuild b/reactos/ReactOS-generic.rbuild
index 96debc3d6dd..6bff3736313 100644
--- a/reactos/ReactOS-generic.rbuild
+++ b/reactos/ReactOS-generic.rbuild
@@ -24,6 +24,7 @@
 	<include root="intermediate">include/psdk</include>
 	<include>include/dxsdk</include>
 	<include>include/crt</include>
+	<include>include/crt/mingw32</include>
 	<include>include/ddk</include>
 	<include>include/GL</include>
 	<include>include/ndk</include>
diff --git a/reactos/lib/sdk/crt/signal/signal.c b/reactos/lib/sdk/crt/signal/signal.c
index 07b7dd3dc9d..e08b6d59d62 100644
--- a/reactos/lib/sdk/crt/signal/signal.c
+++ b/reactos/lib/sdk/crt/signal/signal.c
@@ -6,9 +6,6 @@
 
 void _default_handler(int signal);
 
-typedef void (*__p_sig_fn_t)(int);
-
-
 typedef struct _sig_element
 {
    int signal;
diff --git a/reactos/tools/rbuild/backend/mingw/modulehandler.cpp b/reactos/tools/rbuild/backend/mingw/modulehandler.cpp
index 1c548e2adfe..05d9c63a7b8 100644
--- a/reactos/tools/rbuild/backend/mingw/modulehandler.cpp
+++ b/reactos/tools/rbuild/backend/mingw/modulehandler.cpp
@@ -1945,7 +1945,21 @@ MingwModuleHandler::GenerateOtherMacros ()
 	if ( !module.allowWarnings )
 		globalCflags += " -Werror";
 	if ( module.host == HostTrue )
-		globalCflags += " $(HOST_CFLAGS)";
+	{
+		if ( module.cplusplus )
+			globalCflags += " $(HOST_CPPFLAGS)";
+		else
+			globalCflags += " $(HOST_CFLAGS)";
+	}
+	else
+	{
+		globalCflags += " -nostdinc";
+		if ( module.cplusplus )
+		{
+			// HACK: use host headers when building C++
+			globalCflags += " $(HOST_CPPFLAGS)";
+		}
+	}
 
 	// Always force disabling of sibling calls optimisation for GCC
 	// (TODO: Move to version-specific once this bug is fixed in GCC)