diff --git a/dlls/infosoft/Makefile.in b/dlls/infosoft/Makefile.in
index f7c1bbfcfce..3acc7c97017 100644
--- a/dlls/infosoft/Makefile.in
+++ b/dlls/infosoft/Makefile.in
@@ -5,7 +5,6 @@ C_SRCS = \
 	infosoft_main.c \
 	wordbreaker.c
 
-IDL_H_SRCS = infosoft.idl
 IDL_R_SRCS = infosoft.idl
 
 @MAKE_DLL_RULES@
diff --git a/dlls/jscript/Makefile.in b/dlls/jscript/Makefile.in
index cb041b22467..9078b04651b 100644
--- a/dlls/jscript/Makefile.in
+++ b/dlls/jscript/Makefile.in
@@ -30,7 +30,6 @@ RC_SRCS = jscript.rc
 
 IDL_TLB_SRCS = jsglobal.idl
 IDL_R_SRCS = jscript_classes.idl
-IDL_H_SRCS = jscript_classes.idl
 
 BISON_SRCS = \
 	parser.y
diff --git a/dlls/mshtml/tests/Makefile.in b/dlls/mshtml/tests/Makefile.in
index e3391753b80..64711569ab7 100644
--- a/dlls/mshtml/tests/Makefile.in
+++ b/dlls/mshtml/tests/Makefile.in
@@ -12,7 +12,6 @@ C_SRCS = \
 	style.c
 
 IDL_TLB_SRCS = test_tlb.idl
-IDL_H_SRCS = test_tlb.idl
 
 RC_SRCS = rsrc.rc
 
diff --git a/dlls/msi/Makefile.in b/dlls/msi/Makefile.in
index cba9c031c4f..36cf303d528 100644
--- a/dlls/msi/Makefile.in
+++ b/dlls/msi/Makefile.in
@@ -44,7 +44,6 @@ C_SRCS = \
 	upgrade.c \
 	where.c
 
-IDL_H_SRCS = msiserver.idl
 IDL_I_SRCS = msiserver.idl
 IDL_R_SRCS = msiserver.idl
 IDL_TLB_SRCS = msiserver.idl
diff --git a/dlls/msxml3/Makefile.in b/dlls/msxml3/Makefile.in
index 1e056cfbd55..ed4c039ba10 100644
--- a/dlls/msxml3/Makefile.in
+++ b/dlls/msxml3/Makefile.in
@@ -47,8 +47,6 @@ RC_SRCS = \
 
 IDL_R_SRCS = xmlparser.idl
 
-IDL_H_SRCS = xmlparser.idl
-
 IDL_TLB_SRCS = msxml3_v1.idl
 
 @MAKE_DLL_RULES@
diff --git a/dlls/scrrun/Makefile.in b/dlls/scrrun/Makefile.in
index cb5d981cad5..362cba79cb3 100644
--- a/dlls/scrrun/Makefile.in
+++ b/dlls/scrrun/Makefile.in
@@ -10,6 +10,4 @@ RC_SRCS = scrrun.rc
 
 IDL_TLB_SRCS = scrrun.idl
 
-IDL_H_SRCS = scrrun.idl
-
 @MAKE_DLL_RULES@
diff --git a/dlls/vbscript/Makefile.in b/dlls/vbscript/Makefile.in
index 5bc66cf5d21..381dfd13277 100644
--- a/dlls/vbscript/Makefile.in
+++ b/dlls/vbscript/Makefile.in
@@ -18,11 +18,6 @@ BISON_SRCS = \
 
 RC_SRCS = vbscript.rc
 
-IDL_H_SRCS = \
-	vbscript_classes.idl \
-	vbsglobal.idl \
-	vbsregexp55.idl
-
 IDL_TLB_SRCS = \
 	vbsglobal.idl \
 	vbsregexp10.idl \
diff --git a/dlls/wbemdisp/Makefile.in b/dlls/wbemdisp/Makefile.in
index 3f3ff499314..dbd76d9b2f3 100644
--- a/dlls/wbemdisp/Makefile.in
+++ b/dlls/wbemdisp/Makefile.in
@@ -6,7 +6,6 @@ C_SRCS = \
 	main.c
 
 IDL_R_SRCS = wbemdisp_classes.idl
-IDL_H_SRCS = wbemdisp_classes.idl
 
 IDL_TLB_SRCS = wbemdisp_tlb.idl
 
diff --git a/dlls/wshom.ocx/Makefile.in b/dlls/wshom.ocx/Makefile.in
index 6635e5df80b..9d49bde28ea 100644
--- a/dlls/wshom.ocx/Makefile.in
+++ b/dlls/wshom.ocx/Makefile.in
@@ -7,7 +7,6 @@ C_SRCS = \
 
 RC_SRCS = wshom.rc
 
-IDL_H_SRCS = wshom.idl
 IDL_TLB_SRCS = wshom.idl
 
 @MAKE_DLL_RULES@
diff --git a/programs/wscript/Makefile.in b/programs/wscript/Makefile.in
index 2f4074e3795..2e85e3526e7 100644
--- a/programs/wscript/Makefile.in
+++ b/programs/wscript/Makefile.in
@@ -10,7 +10,6 @@ C_SRCS = \
 	host.c \
 	main.c
 
-IDL_H_SRCS = ihost.idl
 IDL_TLB_SRCS = ihost.idl
 
 @MAKE_PROG_RULES@
diff --git a/tools/make_makefiles b/tools/make_makefiles
index 6b6cdb93f87..13106e7f964 100755
--- a/tools/make_makefiles
+++ b/tools/make_makefiles
@@ -485,7 +485,7 @@ sub assign_sources_to_makefiles(@)
             {
                 my %flags = get_makedep_flags( $file );
                 push @{${$make}{"=IDL_C_SRCS"}}, $name if defined $flags{"client"};
-                push @{${$make}{"=IDL_H_SRCS"}}, $name if defined $flags{"header"};
+                push @{${$make}{"=IDL_H_SRCS"}}, $name if defined $flags{"header"} || !(keys %flags);
                 push @{${$make}{"=IDL_I_SRCS"}}, $name if defined $flags{"ident"};
                 push @{${$make}{"=IDL_P_SRCS"}}, $name if defined $flags{"proxy"};
                 push @{${$make}{"=IDL_R_SRCS"}}, $name if defined $flags{"register"};
@@ -510,6 +510,7 @@ sub assign_sources_to_makefiles(@)
     unshift @{${$make}{"=SRCDIR_INCLUDES"}}, "\$(XTEMPLATE_SRCS)";
     unshift @{${$make}{"=SRCDIR_INCLUDES"}}, "\$(PUBLIC_IDL_H_SRCS)";
     unshift @{${$make}{"=SRCDIR_INCLUDES"}}, "\$(IDL_TLB_SRCS)";
+    unshift @{${$make}{"=IDL_H_SRCS"}}, "\$(PUBLIC_IDL_H_SRCS) \$(PRIVATE_IDL_H_SRCS)";
 
     # preserve shared source files from the parent makefile
     foreach my $file (@makefiles)
@@ -619,6 +620,7 @@ sub update_makefiles(@)
         replace_makefile_variable( $file, "PRIVATE_IDL_H_SRCS" );
         replace_makefile_variable( $file, "PUBLIC_IDL_H_SRCS" );
         replace_makefile_variable( $file, "IDL_C_SRCS" );
+        replace_makefile_variable( $file, "IDL_H_SRCS" );
         replace_makefile_variable( $file, "IDL_I_SRCS" );
         replace_makefile_variable( $file, "IDL_P_SRCS" );
         replace_makefile_variable( $file, "IDL_R_SRCS" );