diff --git a/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java b/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java
index bd1c5a768..5bdc84c7d 100644
--- a/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java
+++ b/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java
@@ -63,6 +63,7 @@ import org.teavm.model.classes.TagRegistry;
 import org.teavm.model.classes.VirtualTable;
 import org.teavm.model.classes.VirtualTableEntry;
 import org.teavm.model.instructions.AbstractInstructionVisitor;
+import org.teavm.model.instructions.CastInstruction;
 import org.teavm.model.instructions.ClassConstantInstruction;
 import org.teavm.model.instructions.ConstructArrayInstruction;
 import org.teavm.model.instructions.ConstructInstruction;
@@ -190,6 +191,11 @@ public class ClassGenerator {
             addType(insn.getType());
         }
 
+        @Override
+        public void visit(CastInstruction insn) {
+            addType(insn.getTargetType());
+        }
+
         @Override
         public void visit(ConstructMultiArrayInstruction insn) {
             ValueType type = insn.getItemType();