diff --git a/core.d b/core.d
index 50f3a3e..b6bf900 100644
--- a/core.d
+++ b/core.d
@@ -9486,7 +9486,13 @@ class LoggerOf(T, size_t bufferSize = 16) : SynchronizableObject {
 						logger.condition.notifyAll();
 					}
 					// mark us as complete for other listeners waiting as well
-					event.set();
+					static if (__traits(hasMember, event, "setIfInitialized")) {
+						// Upstream compatibility, see <https://github.com/dlang/dmd/pull/15800>.
+						event.setIfInitialized();
+					} else {
+						// Old D runtime compatibility
+						event.set();
+					}
 				}
 				+/
 
@@ -9537,7 +9543,13 @@ class LoggerOf(T, size_t bufferSize = 16) : SynchronizableObject {
 					logger.condition.notifyAll();
 				}
 				// mark us as complete for other listeners waiting as well
-				event.set();
+				static if (__traits(hasMember, event, "setIfInitialized")) {
+					// Upstream compatibility, see <https://github.com/dlang/dmd/pull/15800>.
+					event.setIfInitialized();
+				} else {
+					// Old D runtime compatibility
+					event.set();
+				}
 
 			}