diff --git a/prism/src/explicit/MDPModelChecker.java b/prism/src/explicit/MDPModelChecker.java
index 6bacb884..55902975 100644
--- a/prism/src/explicit/MDPModelChecker.java
+++ b/prism/src/explicit/MDPModelChecker.java
@@ -584,6 +584,7 @@ public class MDPModelChecker extends ProbModelChecker
 			// Export
 			PrismLog out = new PrismFileLog(exportAdvFilename);
 			new DTMCFromMDPMemorylessAdversary(mdp, strat).exportToPrismExplicitTra(out);
+			out.close();
 		}
 
 		// Update time taken
@@ -1481,6 +1482,7 @@ public class MDPModelChecker extends ProbModelChecker
 			// Export
 			PrismLog out = new PrismFileLog(exportAdvFilename);
 			new DTMCFromMDPMemorylessAdversary(mdp, strat).exportToPrismExplicitTra(out);
+			out.close();
 		}
 
 		// Finished expected reachability
diff --git a/prism/src/explicit/STPGModelChecker.java b/prism/src/explicit/STPGModelChecker.java
index 8ac7ce33..bda97150 100644
--- a/prism/src/explicit/STPGModelChecker.java
+++ b/prism/src/explicit/STPGModelChecker.java
@@ -644,6 +644,7 @@ public class STPGModelChecker extends ProbModelChecker
 				out.println(i + " " + (adv[i] != -1 ? stpg.getAction(i, adv[i]) : "-"));
 			}
 			out.println();
+			out.close();
 		}
 
 		// Return results
diff --git a/prism/src/prism/NondetModelChecker.java b/prism/src/prism/NondetModelChecker.java
index 72588c42..4c7b9487 100644
--- a/prism/src/prism/NondetModelChecker.java
+++ b/prism/src/prism/NondetModelChecker.java
@@ -1495,7 +1495,9 @@ public class NondetModelChecker extends NonProbModelChecker
 		}
 		if (prism.getExportProductStates()) {
 			mainLog.println("\nExporting product state space to file \"" + prism.getExportProductStatesFilename() + "\"...");
-			modelProduct.exportStates(Prism.EXPORT_PLAIN, new PrismFileLog(prism.getExportProductStatesFilename()));
+			PrismFileLog out = new PrismFileLog(prism.getExportProductStatesFilename());
+			modelProduct.exportStates(Prism.EXPORT_PLAIN, out);
+			out.close();
 		}
 
 		// Find accepting MECs + compute reachability probabilities
diff --git a/prism/src/prism/ProbModelChecker.java b/prism/src/prism/ProbModelChecker.java
index ffed90ff..e660feed 100644
--- a/prism/src/prism/ProbModelChecker.java
+++ b/prism/src/prism/ProbModelChecker.java
@@ -603,7 +603,9 @@ public class ProbModelChecker extends NonProbModelChecker
 		}
 		if (prism.getExportProductStates()) {
 			mainLog.println("\nExporting product state space to file \"" + prism.getExportProductStatesFilename() + "\"...");
-			modelProduct.exportStates(Prism.EXPORT_PLAIN, new PrismFileLog(prism.getExportProductStatesFilename()));
+			PrismFileLog out = new PrismFileLog(prism.getExportProductStatesFilename());
+			modelProduct.exportStates(Prism.EXPORT_PLAIN, out);
+			out.close();
 		}
 
 		// Find accepting BSCCs + compute reachability probabilities
diff --git a/prism/src/simulator/SimulatorEngine.java b/prism/src/simulator/SimulatorEngine.java
index 45efadd6..d3b0c534 100644
--- a/prism/src/simulator/SimulatorEngine.java
+++ b/prism/src/simulator/SimulatorEngine.java
@@ -1319,6 +1319,8 @@ public class SimulatorEngine extends PrismComponent
 			log.println();
 		}
 		((PathFull) path).exportToLog(log, timeCumul, colSep, vars);
+		if (file != null)
+			log.close();
 	}
 
 	/**