diff --git a/.gitignore b/.gitignore
index 58fc2ab5fc3..cb7dc40e06d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@
 /tags
 /wine
 Makefile
+dlldata.c
 dlls/Makedll.rules
 dlls/Makeimplib.rules
 dlls/Maketest.rules
diff --git a/Make.rules.in b/Make.rules.in
index 757fff5511b..24d34dbc0f3 100644
--- a/Make.rules.in
+++ b/Make.rules.in
@@ -114,7 +114,7 @@ IDL_GEN_C_SRCS  = $(IDL_C_SRCS:.idl=_c.c) $(IDL_I_SRCS:.idl=_i.c) \
 IDL_GEN_HEADERS = $(IDL_H_SRCS:.idl=.h) $(IDL_C_SRCS:.idl=.h) $(IDL_I_SRCS:.idl=.h) \
                   $(IDL_P_SRCS:.idl=.h) $(IDL_S_SRCS:.idl=.h)
 
-CLEAN_TARGETS = $(IDL_GEN_C_SRCS) $(IDL_GEN_HEADERS) $(IDL_TLB_SRCS:.idl=.tlb) \
+CLEAN_TARGETS = $(IDL_GEN_C_SRCS) $(IDL_GEN_HEADERS) $(IDL_TLB_SRCS:.idl=.tlb) $(IDL_P_SRCS:%=dlldata.c) \
                 $(BISON_SRCS:.y=.tab.c) $(BISON_SRCS:.y=.tab.h) $(LEX_SRCS:.l=.yy.c) \
                 $(MC_SRCS:.mc=.mc.rc) $(RC_SRCS:.rc=.res) $(RC_SRCS16:.rc=.res)
 
@@ -193,6 +193,11 @@ filter: dummy
 
 .PHONY: all filter
 
+# Rules for IDL files
+
+dlldata.c: $(WIDL) Makefile.in
+	$(WIDL) $(IDLFLAGS) --dlldata-only --dlldata=$@ $(IDL_P_SRCS)
+
 # Rules for resources
 
 $(RC_SRCS:.rc=.res) $(RC_SRCS16:.rc=.res): $(WRC) $(IDL_TLB_SRCS:.idl=.tlb)
diff --git a/tools/make_makefiles b/tools/make_makefiles
index 847a45ea1b9..c988d747150 100755
--- a/tools/make_makefiles
+++ b/tools/make_makefiles
@@ -77,6 +77,7 @@ my @ignores = (
     "/TAGS",
     "/tags",
     "Makefile",
+    "dlldata.c",
     "include/config.h",
     "include/stamp-h"
 );
diff --git a/tools/widl/widl.c b/tools/widl/widl.c
index 0dcc0690bde..79456942609 100644
--- a/tools/widl/widl.c
+++ b/tools/widl/widl.c
@@ -225,7 +225,7 @@ typedef struct
 static void add_filename_node(struct list *list, const char *name)
 {
   filename_node_t *node = xmalloc(sizeof *node);
-  node->filename = xstrdup(name);
+  node->filename = dup_basename( name, ".idl" );
   list_add_tail(list, &node->link);
 }