diff --git a/internal/container/container.go b/internal/container/container.go
index ad2796b84..9280ef0c5 100644
--- a/internal/container/container.go
+++ b/internal/container/container.go
@@ -1314,16 +1314,27 @@ func NewDuckDB() (*sql.DB, error) {
 		return nil, fmt.Errorf("failed to open duckdb: %w", err)
 	}
 
-	// Try to install and load required extensions.
+	// Try to install and load required extensions unless explicitly disabled.
 	//   - spatial: used for st_read_meta() to enumerate layer (sheet) names from .xlsx/.xls
 	//   - excel:   used for read_xlsx() which gives proper type inference per sheet
-	bgCtx := context.Background()
-	for _, ext := range []string{"spatial", "excel"} {
-		if _, err := sqlDB.ExecContext(bgCtx, fmt.Sprintf("INSTALL %s;", ext)); err != nil {
-			logger.Warnf(bgCtx, "[DuckDB] Failed to install %s extension: %v", ext, err)
-		}
-		if _, err := sqlDB.ExecContext(bgCtx, fmt.Sprintf("LOAD %s;", ext)); err != nil {
-			logger.Warnf(bgCtx, "[DuckDB] Failed to load %s extension: %v", ext, err)
+	//
+	// INSTALL hits extensions.duckdb.org (public internet). In locked-down
+	// runtimes with no egress, set DUCKDB_SKIP_EXTENSION_LOAD=1 to avoid a
+	// startup hang; xlsx/xls ingest may fail later without these extensions.
+	if strings.EqualFold(os.Getenv("DUCKDB_SKIP_EXTENSION_LOAD"), "true") ||
+		os.Getenv("DUCKDB_SKIP_EXTENSION_LOAD") == "1" {
+		logger.Infof(context.Background(),
+			"[DuckDB] Skipping spatial/excel extension install/load "+
+				"(DUCKDB_SKIP_EXTENSION_LOAD is set; xlsx ingest may fail without them)")
+	} else {
+		bgCtx := context.Background()
+		for _, ext := range []string{"spatial", "excel"} {
+			if _, err := sqlDB.ExecContext(bgCtx, fmt.Sprintf("INSTALL %s;", ext)); err != nil {
+				logger.Warnf(bgCtx, "[DuckDB] Failed to install %s extension: %v", ext, err)
+			}
+			if _, err := sqlDB.ExecContext(bgCtx, fmt.Sprintf("LOAD %s;", ext)); err != nil {
+				logger.Warnf(bgCtx, "[DuckDB] Failed to load %s extension: %v", ext, err)
+			}
 		}
 	}