diff --git a/jastadd-mquat-solver-ilp/src/main/java/de/tudresden/inf/st/mquat/solving/ilp/GLPKSolver.java b/jastadd-mquat-solver-ilp/src/main/java/de/tudresden/inf/st/mquat/solving/ilp/GLPKSolver.java
index a8976cf27397db245690e16cd613e8e0911e1668..fda2a965c9c2537b2e29830be0004047cc6afe8d 100644
--- a/jastadd-mquat-solver-ilp/src/main/java/de/tudresden/inf/st/mquat/solving/ilp/GLPKSolver.java
+++ b/jastadd-mquat-solver-ilp/src/main/java/de/tudresden/inf/st/mquat/solving/ilp/GLPKSolver.java
@@ -80,7 +80,7 @@ public class GLPKSolver extends ILPExternalSolver {
           }
           phase = 3;
         } else {
-          logger.debug("Tokens: {}", tokens);
+          logger.debug("Tokens: {}", (Object[]) tokens);
         }
       }
     } catch (IOException e) {