diff --git a/src/PowerSystemsInvestmentsPortfolios.jl b/src/PowerSystemsInvestmentsPortfolios.jl
index a5a14a6..c96e1ba 100644
--- a/src/PowerSystemsInvestmentsPortfolios.jl
+++ b/src/PowerSystemsInvestmentsPortfolios.jl
@@ -24,6 +24,7 @@ import JSONSchema
 import JSON3
 import PrettyTables
 import SQLite
+import DataFrames
 
 export Portfolio
 export Technology