diff --git a/configure b/configure
index 39fe5a0542..b40cd836f1 100755
--- a/configure
+++ b/configure
@@ -8439,9 +8439,6 @@ fi
 
 if test x"$with_oauth" = x"curl"; then
 
-$as_echo "#define USE_OAUTH 1" >>confdefs.h
-
-
 $as_echo "#define USE_OAUTH_CURL 1" >>confdefs.h
 
   # OAuth requires python for testing
diff --git a/configure.ac b/configure.ac
index f7e1400b6e..82217e652e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -927,8 +927,7 @@ if test x"$with_oauth" = x"" ; then
 fi
 
 if test x"$with_oauth" = x"curl"; then
-  AC_DEFINE([USE_OAUTH], 1, [Define to 1 to build with OAuth 2.0 support. (--with-oauth)])
-  AC_DEFINE([USE_OAUTH_CURL], 1, [Define to 1 to use libcurl for OAuth support.])
+  AC_DEFINE([USE_OAUTH_CURL], 1, [Define to 1 to build with OAuth 2.0 support. (--with-oauth=curl)])
   # OAuth requires python for testing
   if test "$with_python" != yes; then
     AC_MSG_WARN([*** OAuth support tests requires --with-python to run])
diff --git a/src/backend/libpq/Makefile b/src/backend/libpq/Makefile
index 98eb2a8242..ba502b0442 100644
--- a/src/backend/libpq/Makefile
+++ b/src/backend/libpq/Makefile
@@ -15,7 +15,6 @@ include $(top_builddir)/src/Makefile.global
 # be-fsstubs is here for historical reasons, probably belongs elsewhere
 
 OBJS = \
-	auth-oauth.o \
 	auth-sasl.o \
 	auth-scram.o \
 	auth.o \
@@ -30,6 +29,10 @@ OBJS = \
 	pqmq.o \
 	pqsignal.o
 
+ifneq ($(with_oauth),)
+OBJS += auth-oauth.o
+endif
+
 ifeq ($(with_ssl),openssl)
 OBJS += be-secure-openssl.o
 endif
diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 0cf3e31c9f..57638f922e 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -29,7 +29,6 @@
 #include "libpq/auth.h"
 #include "libpq/crypt.h"
 #include "libpq/libpq.h"
-#include "libpq/oauth.h"
 #include "libpq/pqformat.h"
 #include "libpq/sasl.h"
 #include "libpq/scram.h"
@@ -201,6 +200,14 @@ static int	CheckRADIUSAuth(Port *port);
 static int	PerformRadiusTransaction(const char *server, const char *secret, const char *portstr, const char *identifier, const char *user_name, const char *passwd);
 
 
+/*----------------------------------------------------------------
+ * OAuth Authentication
+ *----------------------------------------------------------------
+ */
+#ifdef USE_OAUTH
+#include "libpq/oauth.h"
+#endif
+
 /*----------------------------------------------------------------
  * Global authentication functions
  *----------------------------------------------------------------
@@ -614,8 +621,13 @@ ClientAuthentication(Port *port)
 		case uaTrust:
 			status = STATUS_OK;
 			break;
+
 		case uaOAuth:
+#ifdef USE_OAUTH
 			status = CheckSASLAuth(&pg_be_oauth_mech, port, NULL, NULL);
+#else
+			Assert(false);
+#endif
 			break;
 	}
 
diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c
index c623b8463d..719c7a881e 100644
--- a/src/backend/libpq/hba.c
+++ b/src/backend/libpq/hba.c
@@ -1749,7 +1749,11 @@ parse_hba_line(TokenizedAuthLine *tok_line, int elevel)
 	else if (strcmp(token->string, "radius") == 0)
 		parsedline->auth_method = uaRADIUS;
 	else if (strcmp(token->string, "oauth") == 0)
+#ifdef USE_OAUTH
 		parsedline->auth_method = uaOAuth;
+#else
+		unsupauth = "oauth";
+#endif
 	else
 	{
 		ereport(elevel,
diff --git a/src/backend/libpq/meson.build b/src/backend/libpq/meson.build
index c85527fb01..1c76dd80cc 100644
--- a/src/backend/libpq/meson.build
+++ b/src/backend/libpq/meson.build
@@ -1,7 +1,6 @@
 # Copyright (c) 2022-2024, PostgreSQL Global Development Group
 
 backend_sources += files(
-  'auth-oauth.c',
   'auth-sasl.c',
   'auth-scram.c',
   'auth.c',
@@ -17,6 +16,10 @@ backend_sources += files(
   'pqsignal.c',
 )
 
+if oauth.found()
+  backend_sources += files('auth-oauth.c')
+endif
+
 if ssl.found()
   backend_sources += files('be-secure-openssl.c')
 endif
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 2f4e3a8f63..a60df328bb 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -703,10 +703,7 @@
 /* Define to select named POSIX semaphores. */
 #undef USE_NAMED_POSIX_SEMAPHORES
 
-/* Define to 1 to build with OAuth 2.0 support. (--with-oauth) */
-#undef USE_OAUTH
-
-/* Define to 1 to use libcurl for OAuth support. */
+/* Define to 1 to build with OAuth 2.0 support. (--with-oauth=curl) */
 #undef USE_OAUTH_CURL
 
 /* Define to 1 to build with OpenSSL support. (--with-ssl=openssl) */
diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index e49eb13e43..9bd655e306 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -172,6 +172,14 @@
 #define USE_SSL
 #endif
 
+/*
+ * USE_OAUTH code should be compiled only when compiling with OAuth support
+ * enabled.
+ */
+#ifdef USE_OAUTH_CURL
+#define USE_OAUTH
+#endif
+
 /*
  * This is the default directory in which AF_UNIX socket files are
  * placed.  Caution: changing this risks breaking your existing client
diff --git a/src/test/modules/oauth_validator/t/001_server.pl b/src/test/modules/oauth_validator/t/001_server.pl
index 3f06f5be76..46684a56e0 100644
--- a/src/test/modules/oauth_validator/t/001_server.pl
+++ b/src/test/modules/oauth_validator/t/001_server.pl
@@ -19,7 +19,7 @@ if (!$ENV{PG_TEST_EXTRA} || $ENV{PG_TEST_EXTRA} !~ /\boauth\b/)
 
 if ($ENV{with_oauth} ne 'curl')
 {
-	plan skip_all => 'client-side OAuth not supported by this build';
+	plan skip_all => 'OAuth not supported by this build';
 }
 
 if ($ENV{with_python} ne 'yes')