diff --git a/rules.make b/rules.make
index 2673917e..faa4c914 100644
--- a/rules.make
+++ b/rules.make
@@ -265,7 +265,7 @@ ALL_LIB_DIRS = $(ADDITIONAL_FRAMEWORK_DIRS) $(AUXILIARY_FRAMEWORK_DIRS) \
 
 # The CPLISTFLAGS are the flags used when running the C preprocessor
 # to generate a .plist file from a .cplist file.
-ALL_CPLISTFLAGS = -P
+ALL_CPLISTFLAGS = -P -x c -traditional
 
 ifeq ($(FOUNDATION_LIB), gnu)
   ALL_CPLISTFLAGS += -DGNUSTEP
@@ -438,7 +438,7 @@ $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.cp
 # be generated by gnustep-make from xxxInfo.cplist by running the
 # preprocessor.
 %.plist : %.cplist
-	$(ECHO_PREPROCESSING)$(GENERAL_CPP) \
+	$(ECHO_PREPROCESSING)$(CPP) \
 	          $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPLISTFLAGS))\
 	          $($<_FILE_FLAGS) $< -o $@$(END_ECHO)