diff --git a/pkgs/servers/sql/postgresql/ext/age.nix b/pkgs/servers/sql/postgresql/ext/age.nix
index b80d1c203b2c..695a0093c225 100644
--- a/pkgs/servers/sql/postgresql/ext/age.nix
+++ b/pkgs/servers/sql/postgresql/ext/age.nix
@@ -2,6 +2,8 @@
 
 let
   hashes = {
+    # Issue tracking PostgreSQL 17 support: https://github.com/apache/age/issues/2111
+    # "17" = "";
     "16" = "sha256-sXh/vmGyYj00ALfFVdeql2DZ6nCJQDNKyNgzlOZnPAw=";
     "15" = "sha256-webZWgWZGnSoXwTpk816tjbtHV1UIlXkogpBDAEL4gM=";
     "14" = "sha256-jZXhcYBubpjIJ8M5JHXKV5f6VK/2BkypH3P7nLxZz3E=";
diff --git a/pkgs/servers/sql/postgresql/ext/citus.nix b/pkgs/servers/sql/postgresql/ext/citus.nix
index 28d6139f0a50..b4c08b4ceab1 100644
--- a/pkgs/servers/sql/postgresql/ext/citus.nix
+++ b/pkgs/servers/sql/postgresql/ext/citus.nix
@@ -41,7 +41,10 @@ stdenv.mkDerivation rec {
     # "Our soft policy for Postgres version compatibility is to support Citus'
     # latest release with Postgres' 3 latest releases."
     # https://www.citusdata.com/updates/v12-0/#deprecated_features
-    broken = versionOlder postgresql.version "14";
+    broken = versionOlder postgresql.version "14" ||
+      # PostgreSQL 17 support issue upstream: https://github.com/citusdata/citus/issues/7708
+      # Check after next package update.
+      (versionAtLeast postgresql.version "17" && version == "12.1.2");
     description = "Distributed PostgreSQL as an extension";
     homepage = "https://www.citusdata.com/";
     changelog = "https://github.com/citusdata/citus/blob/${src.rev}/CHANGELOG.md";
diff --git a/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix b/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix
index 42d055a029ae..74bf0b8eda64 100644
--- a/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix
+++ b/pkgs/servers/sql/postgresql/ext/pg_auto_failover.nix
@@ -28,5 +28,8 @@ stdenv.mkDerivation rec {
     maintainers = [ ];
     platforms = postgresql.meta.platforms;
     license = licenses.postgresql;
+    # PostgreSQL 17 support issue upstream: https://github.com/hapostgres/pg_auto_failover/issues/1048
+    # Check after next package update.
+    broken = versionAtLeast postgresql.version "17" && version == "2.1";
   };
 }
diff --git a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix
index e8b3af416ca7..117319e606f0 100644
--- a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix
+++ b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix
@@ -93,7 +93,10 @@ in
 
   meta = with lib; {
     # Upstream removed support for PostgreSQL 12 and 13 on 0.3.0: https://github.com/tensorchord/pgvecto.rs/issues/343
-    broken = stdenv.hostPlatform.isDarwin || (versionOlder postgresql.version "14");
+    broken = stdenv.hostPlatform.isDarwin || (versionOlder postgresql.version "14") ||
+      # PostgreSQL 17 support issue upstream: https://github.com/tensorchord/pgvecto.rs/issues/607
+      # Check after next package update.
+      versionAtLeast postgresql.version "17" && version == "0.3.0";
     description = "Scalable, Low-latency and Hybrid-enabled Vector Search in Postgres";
     homepage = "https://github.com/tensorchord/pgvecto.rs";
     license = licenses.asl20;
diff --git a/pkgs/servers/sql/postgresql/ext/repmgr.nix b/pkgs/servers/sql/postgresql/ext/repmgr.nix
index 565f3fdaf60d..728f3b348c69 100644
--- a/pkgs/servers/sql/postgresql/ext/repmgr.nix
+++ b/pkgs/servers/sql/postgresql/ext/repmgr.nix
@@ -37,6 +37,9 @@ stdenv.mkDerivation rec {
     license = licenses.postgresql;
     platforms = postgresql.meta.platforms;
     maintainers = with maintainers; [ zimbatm ];
+    # PostgreSQL 17 support issue upstream: https://github.com/EnterpriseDB/repmgr/issues/856
+    # Check after next package update.
+    broken = versionAtLeast postgresql.version "17" && version == "5.4.1";
   };
 }
 
diff --git a/pkgs/servers/sql/postgresql/ext/timescaledb.nix b/pkgs/servers/sql/postgresql/ext/timescaledb.nix
index bd2d2d3b74be..60e14e922835 100644
--- a/pkgs/servers/sql/postgresql/ext/timescaledb.nix
+++ b/pkgs/servers/sql/postgresql/ext/timescaledb.nix
@@ -41,6 +41,11 @@ stdenv.mkDerivation rec {
     maintainers = [ ];
     platforms = postgresql.meta.platforms;
     license = with licenses; if enableUnfree then tsl else asl20;
-    broken = versionOlder postgresql.version "13";
+    broken = versionOlder postgresql.version "13" ||
+      # timescaledb supports PostgreSQL 17 from 2.17.0 on:
+      # https://github.com/timescale/timescaledb/releases/tag/2.17.0
+      # We can't upgrade to it, yet, because this would imply dropping support for
+      # PostgreSQL 13, which is a breaking change.
+      (versionAtLeast postgresql.version "17" && version == "2.14.2");
   };
 }
diff --git a/pkgs/servers/sql/postgresql/ext/timescaledb_toolkit.nix b/pkgs/servers/sql/postgresql/ext/timescaledb_toolkit.nix
index 0776fcb4468a..ab414a400d29 100644
--- a/pkgs/servers/sql/postgresql/ext/timescaledb_toolkit.nix
+++ b/pkgs/servers/sql/postgresql/ext/timescaledb_toolkit.nix
@@ -39,5 +39,8 @@
     maintainers = with maintainers; [ typetetris ];
     platforms = postgresql.meta.platforms;
     license = licenses.tsl;
+    # PostgreSQL 17 support issue upstream: https://github.com/timescale/timescaledb-toolkit/issues/813
+    # Check after next package update.
+    broken = versionAtLeast postgresql.version "17" && version == "1.18.0";
   };
 }