diff --git a/README.md b/README.md
index 1f499be3..0ec7bc63 100644
--- a/README.md
+++ b/README.md
@@ -49,11 +49,11 @@ a link to this page somewhere in the documentation/system about section.
 * :sparkles: :sparkles: :tada: :sparkles: :tada: :sparkles: :rainbow: :sparkles: :sparkles: :sparkles: BPjs now uses Rhino's native continuation equality and hash code ([#116](https://github.com/bThink-BGU/BPjs/issues/116). Also, :tada: :rainbow: :sparkles:.
 * :arrow_up: Scope and context creations across BPjs have been consolidated to utility methods in a new class called `BPjs`.
 * :arrow_up: Event selection strategies that ignore the synchronization statement data field, issue a warning when b-threads put data there ([#151](https://github.com/bThink-BGU/BPjs/issues/151)).
+* :arrow_up: Default priorities in `PrioritizedBSyncEventSelectionStrategy` and `PrioritizedBThreadsEventSelectionStrategy` can be changed ([#115](https://github.com/bThink-BGU/BPjs/issues/115) and [PR#147](https://github.com/bThink-BGU/BPjs/pull/147)).
 * :arrow_up: Updated docs.
 * :arrow_up: `BProgram` uses an override-able protected method to access its global scope, in case you want to intercept these calls.
 * :bug: Fixed an issue that caused `toString` for JavaScript objects to crash at certain cases ([#145](https://github.com/bThink-BGU/BPjs/issues/145)).
 
-
 ### 2021-01
 
 * :sparkles: `BProgramSyncSnapshot`s are serialized using a single stream, and with the b-program's original scope as a top-level scope (([#126](https://github.com/bThink-BGU/BPjs/issues/126)).
@@ -62,21 +62,21 @@ a link to this page somewhere in the documentation/system about section.
 * :sparkles: Another easy event set composition/creation added: `bp.eventSets` gives access to `EventSets`, with methods such as `bp.eventSets.anyOf(...)` and `bp.eventSets.not(...)`
 * :arrow_up: Logging now allows formatting, using Java's MessageFormat.
 * :arrow_up: Expressive `toString` on JavaScript sets ([#135](https://github.com/bThink-BGU/BPjs/issues/135)).
-* :arrow_up: Error messages when passing non-events to a synchronization statement are more informative (([#131](https://github.com/bThink-BGU/BPjs/issues/131)).
+* :arrow_up: Error messages when passing non-events to a synchronization statement are more informative ([#131](https://github.com/bThink-BGU/BPjs/issues/131)).
 * :arrow_up: Improved logging consistency ([#132](https://github.com/bThink-BGU/BPjs/issues/132)).
-* :arrow_up: Error messages when JS event sets do not return a `Boolean` are more informative (([#138](https://github.com/bThink-BGU/BPjs/issues/138)).
-* :arrow_up: BThread data documentation updated (([#134](https://github.com/bThink-BGU/BPjs/issues/134)).
-* :arrow_up: BProgram storage can be updated by the b-program before b-threads run (([#129](https://github.com/bThink-BGU/BPjs/issues/129)).
-* :arrow_up: Changes made to the b-program store after the last sync of a b-thread are now applied (([#130](https://github.com/bThink-BGU/BPjs/issues/130)).
+* :arrow_up: Error messages when JS event sets do not return a `Boolean` are more informative ([#138](https://github.com/bThink-BGU/BPjs/issues/138)).
+* :arrow_up: BThread data documentation updated ([#134](https://github.com/bThink-BGU/BPjs/issues/134)).
+* :arrow_up: BProgram storage can be updated by the b-program before b-threads run ([#129](https://github.com/bThink-BGU/BPjs/issues/129)).
+* :arrow_up: Changes made to the b-program store after the last sync of a b-thread are now applied ([#130](https://github.com/bThink-BGU/BPjs/issues/130)).
 * :arrow_up: More tests (logger, JSProxy, ScriptableUtils, OrderedSet, JsEventSet, some event selection strategies).
-* :bug: :tada: JS-semantics are applied for `equals` and `hashCode` for b-thread and b-program data (([#144](https://github.com/bThink-BGU/BPjs/issues/144)).
+* :bug: :tada: JS-semantics are applied for `equals` and `hashCode` for b-thread and b-program data ([#144](https://github.com/bThink-BGU/BPjs/issues/144)).
 * :bug: Fixed the note color issue in the documentation ([#137](https://github.com/bThink-BGU/BPjs/issues/137)).
 * :bug: Fixed the bench marker.
 * :bug: Fixes a crash when a JS event set predicate returns `null` instead of a boolean.
 * :put_litter_in_its_place: Significant cleanup of the b-program I/O area.
 * :put_litter_in_its_place: Significant cleanup of the event set area. Some methods moved from `ComposableEventSet` to `EventSets`.
 * :put_litter_in_its_place: Some documentation updates and corrections.
-* :put_litter_in_its_place: Removed extraneous dependencies from `pom.xml` (([#133](https://github.com/bThink-BGU/BPjs/issues/133)).
+* :put_litter_in_its_place: Removed extraneous dependencies from `pom.xml` ([#133](https://github.com/bThink-BGU/BPjs/issues/133)).
 
 [Earlier Changes](changelog-2020.md)
 
diff --git a/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategy.java b/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategy.java
index eff190e2..37ebe8c0 100644
--- a/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategy.java
+++ b/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategy.java
@@ -49,7 +49,9 @@
  * @author michael
  */
 public class PrioritizedBSyncEventSelectionStrategy extends AbstractEventSelectionStrategy {
-
+    
+    private int defaultPriority = Integer.MIN_VALUE;
+    
     public PrioritizedBSyncEventSelectionStrategy(long seed) {
         super(seed);
     }
@@ -83,7 +85,7 @@ public Set<BEvent> selectableEvents(BProgramSyncSnapshot bpss) {
                                  .collect( toSet() );
             } else {
                 // Can't select any internal event, defer to the external, non-blocked ones.
-                return externalEvents.stream().filter( e->!blocked.contains(e) ) // No internal events requested, defer to externals.
+                return externalEvents.stream().filter( e->!blocked.contains(e) ) 
                                       .findFirst().map( e->singleton(e) ).orElse(emptySet());
             }
         } finally {
@@ -94,8 +96,15 @@ public Set<BEvent> selectableEvents(BProgramSyncSnapshot bpss) {
     
     private int getValue( SyncStatement stmt ) {
         return (stmt.hasData() && (stmt.getData() instanceof Number))? 
-                ((Number)stmt.getData()).intValue() : Integer.MIN_VALUE;
+                ((Number)stmt.getData()).intValue() : defaultPriority;
+    }
+
+    public int getDefaultPriority() {
+        return defaultPriority;
+    }
+
+    public void setDefaultPriority(int defaultPriority) {
+        this.defaultPriority = defaultPriority;
     }
 
-    
 }
\ No newline at end of file
diff --git a/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategy.java b/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategy.java
index c0db7edc..de8f0b0b 100644
--- a/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategy.java
+++ b/src/main/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategy.java
@@ -33,7 +33,7 @@
  */
 public class PrioritizedBThreadsEventSelectionStrategy extends AbstractEventSelectionStrategy {
 
-    public static final int DEFAULT_PRIORITY = -1;
+    private int defaultPriority = -1;
     
     /** A mapping of b-thread names to their priorities. */
     final private Map<String, Integer> priorities = new HashMap<>();
@@ -113,15 +113,23 @@ public void setPriority(String bThreadName, Integer priority) {
     }
     
     public int getPriority(String bThreadName) {
-    	return priorities.getOrDefault(bThreadName, DEFAULT_PRIORITY);
+    	return priorities.getOrDefault(bThreadName, defaultPriority);
     }
     
     public int getHighestPriority() {
-        return priorities.values().stream().mapToInt( Integer::intValue ).max().orElse(DEFAULT_PRIORITY);
+        return priorities.values().stream().mapToInt( Integer::intValue ).max().orElse(defaultPriority);
     }
     
     public int getLowestPriority() {
-        return priorities.values().stream().mapToInt( Integer::intValue ).min().orElse(DEFAULT_PRIORITY);
+        return priorities.values().stream().mapToInt( Integer::intValue ).min().orElse(defaultPriority);
+    }
+
+    public int getDefaultPriority() {
+        return defaultPriority;
+    }
+
+    public void setDefaultPriority(int defaultPriority) {
+        this.defaultPriority = defaultPriority;
     }
     
 }
diff --git a/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategyTest.java b/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategyTest.java
index e7d22718..d549581f 100644
--- a/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategyTest.java
+++ b/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBSyncEventSelectionStrategyTest.java
@@ -7,7 +7,6 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.Set;
 
 import org.junit.Test;
 
@@ -34,6 +33,21 @@ public void testSelectableEvents_noBlocking() throws InterruptedException {
         );
 		assertEquals(new HashSet<>(Arrays.asList(EVT_2, EVT_3)), sut.selectableEvents(bpss));
 	}
+    
+    @Test
+	public void testSelectableEvents_changedPriority() throws InterruptedException {
+		PrioritizedBSyncEventSelectionStrategy sut = new PrioritizedBSyncEventSelectionStrategy();
+        sut.setDefaultPriority(11);
+        
+		BProgramSyncSnapshot bpss = TestUtils.makeBPSS(
+            new MockBThreadSyncSnapshot(SyncStatement.make().request(Arrays.asList(EVT_4))),
+            new MockBThreadSyncSnapshot(SyncStatement.make().request(Arrays.asList(EVT_1)).data(5)),
+            new MockBThreadSyncSnapshot(SyncStatement.make().request(Arrays.asList(EVT_2)).data(10)),
+            new MockBThreadSyncSnapshot(SyncStatement.make().request(Arrays.asList(EVT_3)).data(10))
+        );
+		assertEquals(new HashSet<>(Arrays.asList(EVT_4)), sut.selectableEvents(bpss));
+		assertEquals(11, sut.getDefaultPriority());
+	}
 
 	@Test
 	public void testSelectableEvents_withBlocking() {
diff --git a/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategyTest.java b/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategyTest.java
index 4bec2cc5..6a8d9c53 100644
--- a/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategyTest.java
+++ b/src/test/java/il/ac/bgu/cs/bp/bpjs/model/eventselection/PrioritizedBThreadsEventSelectionStrategyTest.java
@@ -54,7 +54,6 @@ public void testSelectableEvents_noBlocking_double() throws InterruptedException
             new MockBThreadSyncSnapshot("bt2", SyncStatement.make(bt("2")).request(Arrays.asList(EVT_2))),
             new MockBThreadSyncSnapshot("bt2a", SyncStatement.make(bt("2a")).request(Arrays.asList(EVT_2A)))
         );
-        
 		
 		assertEquals(new HashSet<>(Arrays.asList(EVT_2, EVT_2A)),
 				sut.selectableEvents(bpss));
@@ -129,11 +128,15 @@ public void testPriorityNumbers() {
         assertEquals( 2, sut.getPriority("bt2a") );
         assertEquals( 3, sut.getPriority("bt3") );
         
-        assertEquals( PrioritizedBThreadsEventSelectionStrategy.DEFAULT_PRIORITY,
+        assertEquals( sut.getDefaultPriority(),
                             sut.getPriority("was-not-registered") );
         
         assertEquals( 3, sut.getHighestPriority() );
         assertEquals( 1, sut.getLowestPriority() );
+        
+        sut.setDefaultPriority(300);
+        assertEquals( sut.getDefaultPriority(),
+                            sut.getPriority("was-not-registered") );
     }
     
     private BThreadSyncSnapshot bt( String name ) {