diff --git a/bld/as/client.mif b/bld/as/client.mif
index da8149579e..e189214e9f 100644
--- a/bld/as/client.mif
+++ b/bld/as/client.mif
@@ -9,7 +9,7 @@ asminline_lib = $(as_dir)/$(target_cpu)/$(objs_subdir)/asinline.lib
 # AS in-line run-time DLL used
 #
 asminline_lib = $(as_dir)/$(target_cpu)/$(objs_subdir).rtd/asinline.lib
-!else ifeq $(proj_name)_dll 1
+!else ifdef $(proj_name)_dll
 #
 # AS in-line DLL used
 #
diff --git a/bld/builder/master.mif b/bld/builder/master.mif
index e030a3a5eb..6b552523ed 100644
--- a/bld/builder/master.mif
+++ b/bld/builder/master.mif
@@ -33,16 +33,16 @@ inc_dirs = -I"../h" -I"$(pmake_dir)" -I"$(posix_dir)/h"
 
 .c : ../c;$(pmake_dir);$(posix_dir)/misc;$(watcom_dir)/c;$(trmem_dir)
 
-sys_dos  = sysdos.obj
-sys_nt   = sysnt.obj
-sys_os2  = sysos2.obj
-!ifdef sys_$(host_os)
-sys_objs = $(sys_$(host_os))
+builder_sys_objs_dos  = sysdos.obj
+builder_sys_objs_nt   = sysnt.obj
+builder_sys_objs_os2  = sysos2.obj
+!ifdef builder_sys_objs_$(host_os)
+builder_sys_objs = $(builder_sys_objs_$(host_os))
 !else
-sys_objs = sysposix.obj
+builder_sys_objs = sysposix.obj
 !endif
 
-builder_objs = builder.obj utils.obj $(sys_objs) runit.obj pmake.obj $(bld_cl_extra_objs_gen) $(trmem_objs)
+builder_objs = builder.obj utils.obj $(builder_sys_objs) runit.obj pmake.obj $(bld_cl_extra_objs_gen) $(trmem_objs)
 sweep_objs   = sweep.obj $(bld_cl_extra_objs_gen)
 wsplice_objs = wsplice.obj $(bld_cl_extra_objs_gen)
 diff_objs    = diff.obj $(bld_cl_extra_objs_gen)
diff --git a/bld/cc/master.mif b/bld/cc/master.mif
index 06b7040745..9ad6f0c0a7 100644
--- a/bld/cc/master.mif
+++ b/bld/cc/master.mif
@@ -61,7 +61,7 @@ $(bin_subdir) : .EXPLICIT
 inc_dirs  = -I. -I.. -I"../../h" $(cg_inc_dirs) $(asminline_inc_dirs) $(cpp_inc_dirs) $(dwarfw_inc_dirs) -I"$(comp_cfg_dir)/h" -I"$(fe_misc_dir)/h"
 
 extra_cpp_flags = -DINCL_MSGTEXT
-!ifneq cc_dll 1
+!ifndef cc_dll
 extra_cpp_flags += -DIDE_PGM
 !endif
 !ifeq dll_cg 1
@@ -76,7 +76,7 @@ extra_cpp_flags += -DAS_DEBUG_DUMP
 !endif
 
 extra_cpp_flags_cmsg     = -D__msg_file_prefix=$(intname)
-!ifeq cc_dll 1
+!ifdef cc_dll
 ! ifeq host_os dos
 extra_cpp_flags_ideentry = -DCAUSEWAY
 ! endif
diff --git a/bld/cfloat/client.mif b/bld/cfloat/client.mif
index 8a51b204e1..9449803563 100644
--- a/bld/cfloat/client.mif
+++ b/bld/cfloat/client.mif
@@ -9,7 +9,7 @@ cfloat_lib = $(cfloat_dir)/$(objs_subdir)/cf.lib
 # CFLOAT run-time DLL used
 #
 cfloat_lib = $(cfloat_dir)/$(objs_subdir).rtd/cf.lib
-!else ifeq $(proj_name)_dll 1
+!else ifdef $(proj_name)_dll
 #
 # CFLOAT DLL used
 #
diff --git a/bld/cg/client.mif b/bld/cg/client.mif
index 5b2c4899c1..52eaf5411d 100644
--- a/bld/cg/client.mif
+++ b/bld/cg/client.mif
@@ -12,7 +12,7 @@ obj_dir = $(objs_subdir)
 obj_dir = $(objs_subdir).cgd
 !else ifeq $(proj_name)_rtdll 1
 obj_dir = $(objs_subdir).rtd
-!else ifeq $(proj_name)_dll 1
+!else ifdef $(proj_name)_dll
 obj_dir = $(objs_subdir).dll
 !else ifdef debug_cg
 obj_dir = $(objs_subdir).dbg
diff --git a/bld/dwarf/dw/client.mif b/bld/dwarf/dw/client.mif
index 1bc6cbe94a..6ff4166c24 100644
--- a/bld/dwarf/dw/client.mif
+++ b/bld/dwarf/dw/client.mif
@@ -9,7 +9,7 @@ dwarfw_lib = $(dwarfw_dir)/$(objs_subdir)/dwarfw.lib
 # DWARF run-time DLL used
 #
 dwarfw_lib = $(dwarfw_dir)/$(objs_subdir).rtd/dwarfw.lib
-!else ifeq $(proj_name)_dll 1
+!else ifdef $(proj_name)_dll
 #
 # DWARF DLL used
 #
diff --git a/bld/owl/client.mif b/bld/owl/client.mif
index d5d1bb3645..1a765623ef 100644
--- a/bld/owl/client.mif
+++ b/bld/owl/client.mif
@@ -9,7 +9,7 @@ owl_lib = $(owl_dir)/$(objs_subdir)/owl.lib
 # OWL run-time DLL used
 #
 owl_lib = $(owl_dir)/$(objs_subdir).rtd/owl.lib
-!else ifeq $(proj_name)_dll 1
+!else ifdef $(proj_name)_dll
 #
 # OWL DLL used
 #