diff --git a/cmd/pulse-sensor-proxy/config.example.yaml b/cmd/pulse-sensor-proxy/config.example.yaml
index 11f8b3b..6ebb193 100644
--- a/cmd/pulse-sensor-proxy/config.example.yaml
+++ b/cmd/pulse-sensor-proxy/config.example.yaml
@@ -42,7 +42,7 @@ rate_limit:
 
 # HTTPS mode (for remote nodes)
 http_enabled: false
-http_listen_addr: ":8443"
+http_listen_addr: "0.0.0.0:8443"  # Explicitly IPv4; use [::]:8443 for IPv6
 http_tls_cert: "/etc/pulse-sensor-proxy/tls/server.crt"
 http_tls_key: "/etc/pulse-sensor-proxy/tls/server.key"
 http_auth_token: ""           # Populated by installer; keep secret
diff --git a/cmd/pulse-sensor-proxy/config.go b/cmd/pulse-sensor-proxy/config.go
index e2147b0..d4275fc 100644
--- a/cmd/pulse-sensor-proxy/config.go
+++ b/cmd/pulse-sensor-proxy/config.go
@@ -354,7 +354,10 @@ func loadConfig(configPath string) (*Config, error) {
 	// Validate HTTP configuration if enabled
 	if cfg.HTTPEnabled {
 		if cfg.HTTPListenAddr == "" {
-			cfg.HTTPListenAddr = ":8443" // Default port
+			// Use 0.0.0.0:8443 explicitly for IPv4 binding.
+			// Using just ":8443" can result in IPv6-only binding on systems
+			// with net.ipv6.bindv6only=1 (e.g., some Proxmox 8 configurations).
+			cfg.HTTPListenAddr = "0.0.0.0:8443"
 			log.Info().Str("http_addr", cfg.HTTPListenAddr).Msg("Using default HTTP listen address")
 		}
 		if cfg.HTTPAuthToken == "" {
diff --git a/scripts/install-sensor-proxy.sh b/scripts/install-sensor-proxy.sh
index 7645bf4..0d3e875 100755
--- a/scripts/install-sensor-proxy.sh
+++ b/scripts/install-sensor-proxy.sh
@@ -1155,7 +1155,7 @@ QUIET=false
 PULSE_SERVER=""
 STANDALONE=false
 HTTP_MODE=false
-HTTP_ADDR=":8443"
+HTTP_ADDR="0.0.0.0:8443"  # Explicitly IPv4 to avoid IPv6-only binding on some systems
 FALLBACK_BASE="${PULSE_SENSOR_PROXY_FALLBACK_URL:-}"
 SKIP_RESTART=false
 RESTART_PULSE=false