diff --git a/src/test/java/org/cactoos/map/MapOfTest.java b/src/test/java/org/cactoos/map/MapOfTest.java
index 5e3448abfb..40d6aa3b44 100644
--- a/src/test/java/org/cactoos/map/MapOfTest.java
+++ b/src/test/java/org/cactoos/map/MapOfTest.java
@@ -55,10 +55,11 @@ public void behavesAsMap() {
             "Can't behave as a map",
             new NoNulls<>(
                 new MapOf<Integer, Integer>(
-                    new MapEntry<>(0, 1)
+                    new MapEntry<>(0, -1),
+                    new MapEntry<>(1, 1)
                 )
             ),
-            new BehavesAsMap<>(0, 1)
+            new BehavesAsMap<>(1, 1)
         );
     }
 
diff --git a/src/test/java/org/cactoos/map/SolidTest.java b/src/test/java/org/cactoos/map/SolidTest.java
index d561566f48..1d9388914f 100644
--- a/src/test/java/org/cactoos/map/SolidTest.java
+++ b/src/test/java/org/cactoos/map/SolidTest.java
@@ -52,9 +52,10 @@ public void behavesAsMap() {
         MatcherAssert.assertThat(
             "Can't behave as a map",
             new Solid<Integer, Integer>(
-                new MapEntry<>(0, 1)
+                new MapEntry<>(0, -1),
+                new MapEntry<>(1, 1)
             ),
-            new BehavesAsMap<>(0, 1)
+            new BehavesAsMap<>(1, 1)
         );
     }
 
@@ -66,13 +67,14 @@ public void worksInThreads() {
                 MatcherAssert.assertThat(
                     "Can't behave as a map in thread",
                     map,
-                    new BehavesAsMap<>(0, 1)
+                    new BehavesAsMap<>(1, 1)
                 );
                 return true;
             },
             new RunsInThreads<>(
                 new Solid<Integer, Integer>(
-                    new MapEntry<>(0, 1)
+                    new MapEntry<>(0, -1),
+                    new MapEntry<>(1, 1)
                 )
             )
         );
diff --git a/src/test/java/org/cactoos/map/StickyTest.java b/src/test/java/org/cactoos/map/StickyTest.java
index a104ab67b5..ae7b89ce26 100644
--- a/src/test/java/org/cactoos/map/StickyTest.java
+++ b/src/test/java/org/cactoos/map/StickyTest.java
@@ -51,9 +51,10 @@ public void behavesAsMap() {
         MatcherAssert.assertThat(
             "Can't behave as a map",
             new Sticky<Integer, Integer>(
-                new MapEntry<>(0, 1)
+                new MapEntry<>(0, -1),
+                new MapEntry<>(1, 1)
             ),
-            new BehavesAsMap<>(0, 1)
+            new BehavesAsMap<>(1, 1)
         );
     }
 
diff --git a/src/test/java/org/cactoos/map/SyncedTest.java b/src/test/java/org/cactoos/map/SyncedTest.java
index 1e313e49ee..3c7365ea44 100644
--- a/src/test/java/org/cactoos/map/SyncedTest.java
+++ b/src/test/java/org/cactoos/map/SyncedTest.java
@@ -41,9 +41,10 @@ public void behavesAsMap() {
         MatcherAssert.assertThat(
             "Can't behave as a map",
             new Synced<Integer, Integer>(
-                new MapEntry<>(0, 1)
+                new MapEntry<>(0, -1),
+                new MapEntry<>(1, 1)
             ),
-            new BehavesAsMap<>(0, 1)
+            new BehavesAsMap<>(1, 1)
         );
     }
 
@@ -55,13 +56,14 @@ public void worksInThreads() {
                 MatcherAssert.assertThat(
                     "Can't behave as a map in thread",
                     map,
-                    new BehavesAsMap<>(0, 1)
+                    new BehavesAsMap<>(1, 1)
                 );
                 return true;
             },
             new RunsInThreads<>(
                 new Synced<Integer, Integer>(
-                    new MapEntry<>(0, 1)
+                    new MapEntry<>(0, -1),
+                    new MapEntry<>(1, 1)
                 )
             )
         );