diff --git a/build.gradle.kts b/build.gradle.kts
index f6dbe79f75..f11d9124c4 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -28,7 +28,7 @@ buildscript {
 
 allprojects {
     group = "hu.bme.mit.theta"
-    version = "5.0.5"
+    version = "5.0.6"
 
     apply(from = rootDir.resolve("gradle/shared-with-buildSrc/mirrors.gradle.kts"))
 }
diff --git a/subprojects/solver/solver-smtlib/src/main/java/hu/bme/mit/theta/solver/smtlib/impl/smtinterpol/SMTInterpolSmtLibItpSolver.java b/subprojects/solver/solver-smtlib/src/main/java/hu/bme/mit/theta/solver/smtlib/impl/smtinterpol/SMTInterpolSmtLibItpSolver.java
index 2c73aac4cf..07a3cf340f 100644
--- a/subprojects/solver/solver-smtlib/src/main/java/hu/bme/mit/theta/solver/smtlib/impl/smtinterpol/SMTInterpolSmtLibItpSolver.java
+++ b/subprojects/solver/solver-smtlib/src/main/java/hu/bme/mit/theta/solver/smtlib/impl/smtinterpol/SMTInterpolSmtLibItpSolver.java
@@ -44,6 +44,7 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.IdentityHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -57,7 +58,7 @@
 
 public final class SMTInterpolSmtLibItpSolver extends SmtLibItpSolver<SMTInterpolSmtLibItpMarker> {
 
-    private final Map<Expr<BoolType>, String> assertionNames = new HashMap<>();
+    private final Map<Expr<BoolType>, String> assertionNames = new IdentityHashMap<>();
     private static final String assertionNamePattern = "_smtinterpol_assertion_%d";
     private static long assertionCount = 0;