diff --git a/src/bin/pg_upgrade/Makefile b/src/bin/pg_upgrade/Makefile
index 4eb20d6b54..d9c8145ce0 100644
--- a/src/bin/pg_upgrade/Makefile
+++ b/src/bin/pg_upgrade/Makefile
@@ -11,7 +11,7 @@ OBJS = check.o controldata.o dump.o exec.o file.o function.o info.o \
        option.o page.o parallel.o pg_upgrade.o relfilenode.o server.o \
        tablespace.o util.o version.o $(WIN32RES)
 
-override CPPFLAGS := -DFRONTEND -DDLSUFFIX=\"$(DLSUFFIX)\" -I$(srcdir) -I$(libpq_srcdir) $(CPPFLAGS)
+override CPPFLAGS := -DDLSUFFIX=\"$(DLSUFFIX)\" -I$(srcdir) -I$(libpq_srcdir) $(CPPFLAGS)
 
 
 all: pg_upgrade
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 9d0cf8d01e..f5b97390f8 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -379,7 +379,6 @@ sub mkvcbuild
 	$pgregress_ecpg->AddIncludeDir('src\port');
 	$pgregress_ecpg->AddIncludeDir('src\test\regress');
 	$pgregress_ecpg->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
-	$pgregress_ecpg->AddDefine('FRONTEND');
 	$pgregress_ecpg->AddLibrary('ws2_32.lib');
 	$pgregress_ecpg->AddDirResourceFile('src\interfaces\ecpg\test');
 	$pgregress_ecpg->AddReference($libpgcommon, $libpgport);
@@ -395,7 +394,6 @@ sub mkvcbuild
 	$isolation_tester->AddIncludeDir('src\test\regress');
 	$isolation_tester->AddIncludeDir('src\interfaces\libpq');
 	$isolation_tester->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
-	$isolation_tester->AddDefine('FRONTEND');
 	$isolation_tester->AddLibrary('ws2_32.lib');
 	$isolation_tester->AddDirResourceFile('src\test\isolation');
 	$isolation_tester->AddReference($libpq, $libpgcommon, $libpgport);
@@ -407,7 +405,6 @@ sub mkvcbuild
 	$pgregress_isolation->AddIncludeDir('src\port');
 	$pgregress_isolation->AddIncludeDir('src\test\regress');
 	$pgregress_isolation->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
-	$pgregress_isolation->AddDefine('FRONTEND');
 	$pgregress_isolation->AddLibrary('ws2_32.lib');
 	$pgregress_isolation->AddDirResourceFile('src\test\isolation');
 	$pgregress_isolation->AddReference($libpgcommon, $libpgport);
@@ -640,7 +637,6 @@ sub mkvcbuild
 	$pgregress->AddFile('src\test\regress\pg_regress_main.c');
 	$pgregress->AddIncludeDir('src\port');
 	$pgregress->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
-	$pgregress->AddDefine('FRONTEND');
 	$pgregress->AddLibrary('ws2_32.lib');
 	$pgregress->AddDirResourceFile('src\test\regress');
 	$pgregress->AddReference($libpgcommon, $libpgport);