diff --git a/core/src/main/java/org/teavm/backend/lowlevel/transform/CoroutineTransformation.java b/core/src/main/java/org/teavm/backend/lowlevel/transform/CoroutineTransformation.java
index 540fc00b8..796e4daa4 100644
--- a/core/src/main/java/org/teavm/backend/lowlevel/transform/CoroutineTransformation.java
+++ b/core/src/main/java/org/teavm/backend/lowlevel/transform/CoroutineTransformation.java
@@ -117,6 +117,7 @@ public class CoroutineTransformation {
             processBlock(program.basicBlockAt(i));
         }
         splitter.fixProgram();
+        new PhiUpdater().updatePhis(program, methodReference.parameterCount() + 1);
         processIrreducibleCfg();
     }