diff --git a/src/backend/replication/pgoutput/Makefile b/src/backend/replication/pgoutput/Makefile
index 1b68e2b4b6..cbe444bae3 100644
--- a/src/backend/replication/pgoutput/Makefile
+++ b/src/backend/replication/pgoutput/Makefile
@@ -12,8 +12,6 @@ subdir = src/backend/replication/pgoutput
 top_builddir = ../../../..
 include $(top_builddir)/src/Makefile.global
 
-override CPPFLAGS := -I$(srcdir) $(CPPFLAGS)
-
 OBJS = pgoutput.o $(WIN32RES)
 PGFILEDESC = "pgoutput - standard logical replication output plugin"
 NAME = pgoutput
diff --git a/src/makefiles/Makefile.cygwin b/src/makefiles/Makefile.cygwin
index bb2efed3ce..3aaa8a9f04 100644
--- a/src/makefiles/Makefile.cygwin
+++ b/src/makefiles/Makefile.cygwin
@@ -16,13 +16,15 @@ CFLAGS_SL =
 
 ifneq (,$(findstring backend,$(subdir)))
 ifeq (,$(findstring conversion_procs,$(subdir)))
-ifeq (,$(findstring snowball,$(subdir)))
 ifeq (,$(findstring libpqwalreceiver,$(subdir)))
+ifeq (,$(findstring replication/pgoutput,$(subdir)))
+ifeq (,$(findstring snowball,$(subdir)))
 override CPPFLAGS+= -DBUILDING_DLL
 endif
 endif
 endif
 endif
+endif
 
 ifneq (,$(findstring src/common,$(subdir)))
 override CPPFLAGS+= -DBUILDING_DLL
diff --git a/src/makefiles/Makefile.win32 b/src/makefiles/Makefile.win32
index 5f26a091d2..7abbd01971 100644
--- a/src/makefiles/Makefile.win32
+++ b/src/makefiles/Makefile.win32
@@ -14,13 +14,15 @@ CFLAGS_SL =
 
 ifneq (,$(findstring backend,$(subdir)))
 ifeq (,$(findstring conversion_procs,$(subdir)))
-ifeq (,$(findstring snowball,$(subdir)))
 ifeq (,$(findstring libpqwalreceiver,$(subdir)))
+ifeq (,$(findstring replication/pgoutput,$(subdir)))
+ifeq (,$(findstring snowball,$(subdir)))
 override CPPFLAGS+= -DBUILDING_DLL
 endif
 endif
 endif
 endif
+endif
 
 ifneq (,$(findstring src/common,$(subdir)))
 override CPPFLAGS+= -DBUILDING_DLL