diff --git a/src/main/java/dk/camelot64/kickc/model/Initializers.java b/src/main/java/dk/camelot64/kickc/model/Initializers.java
index d5b5789a3..393a214f2 100644
--- a/src/main/java/dk/camelot64/kickc/model/Initializers.java
+++ b/src/main/java/dk/camelot64/kickc/model/Initializers.java
@@ -89,6 +89,8 @@ public class Initializers {
                return new ConstantCastValue(toType, (ConstantValue) constantSub);
             }
          }
+      } else if(initValue instanceof UnionDesignator) {
+         initValue = constantifyUnion((UnionDesignator) initValue, (SymbolTypeStruct) typeSpec.getType(), program, source);
       } else if(initValue instanceof ValueList) {
          ValueList initList = (ValueList) initValue;
          if(typeSpec.getType() instanceof SymbolTypePointer && ((SymbolTypePointer) typeSpec.getType()).getArraySpec() != null) {
@@ -96,7 +98,7 @@ public class Initializers {
             initValue = constantifyArray(initList, (SymbolTypePointer) typeSpec.getType(), program, source);
          } else if(typeSpec.getType() instanceof SymbolTypeStruct) {
             // Type is a struct
-            initValue = constantifyStruct(initList, (SymbolTypeStruct) typeSpec.getType(), program, source);
+            initValue = constantifyStructOrUnion(initList, (SymbolTypeStruct) typeSpec.getType(), program, source);
          } else {
             throw new CompileError("Value list cannot initialize type " + typeSpec.getType(), source);
          }
@@ -127,6 +129,42 @@ public class Initializers {
       return initValue;
    }
 
+   /**
+    * Convert as much as possible of a struct to constants.
+    *
+    * @param unionInit The value list
+    * @param structType The struct type
+    * @param program The program
+    * @param source The source line
+    * @return The constantified value
+    */
+   private static RValue constantifyUnion(UnionDesignator unionInit, SymbolTypeStruct structType, Program program, StatementSource source) {
+      StructDefinition structDefinition = structType.getStructDefinition(program.getScope());
+      Collection<Variable> memberDefinitions = structDefinition.getAllVars(false);
+
+      final String memberName = unionInit.getMemberName();
+      final RValue initValue = unionInit.getMemberValue();
+
+      Variable memberDef = null;
+      for(Variable definition : memberDefinitions) {
+         if(definition.getLocalName().equals(memberName)) {
+            memberDef = definition;
+         }
+      }
+      if(memberDef==null)
+         throw new CompileError( "Union member not found", source);
+
+      RValue constantifiedMemberValue = constantify(initValue, new ValueTypeSpec(memberDef.getType()), program, source);
+      if(constantifiedMemberValue instanceof ConstantValue) {
+         LinkedHashMap<SymbolVariableRef, ConstantValue> constMemberMap = new LinkedHashMap<>();
+         constMemberMap.put(memberDef.getRef(), (ConstantValue) constantifiedMemberValue);
+         return new ConstantStructValue(structType, constMemberMap);
+      } else {
+         throw new CompileError( "Union initializer is not constant", source);
+      }
+   }
+
+
    /**
     * Convert as much as possible of a struct to constants.
     *
@@ -136,19 +174,17 @@ public class Initializers {
     * @param source The source line
     * @return The constantified value
     */
-   private static RValue constantifyStruct(ValueList valueList, SymbolTypeStruct structType, Program program, StatementSource source) {
+   private static RValue constantifyStructOrUnion(ValueList valueList, SymbolTypeStruct structType, Program program, StatementSource source) {
       // Recursively cast all sub-elements
       StructDefinition structDefinition = structType.getStructDefinition(program.getScope());
       Collection<Variable> memberDefinitions = structDefinition.getAllVars(false);
       int structInitNeedSize = structDefinition.isUnion() ? 1 : memberDefinitions.size();
       if(structInitNeedSize != valueList.getList().size()) {
          if(structDefinition.isUnion()) {
-            if(valueList.getList().size()>1) {
-               throw new CompileError(
-                       "Union initializer has too many values, since only one is allowed.\n" +
-                               " Union initializer: " + valueList.toString(program),
-                       source);
-            }
+            throw new CompileError(
+                  "Union initializer has wrong size. One value is required.\n" +
+                        " Union initializer: " + valueList.toString(program),
+                  source);
          } else {
             throw new CompileError(
                   "Struct initializer has wrong size (" + valueList.getList().size() + "), " +
@@ -159,55 +195,29 @@ public class Initializers {
          }
       }
 
-      if(valueList instanceof ValueListUnionDesignator) {
-
-         ValueListUnionDesignator unionInit = (ValueListUnionDesignator) valueList;
-         final String memberName = unionInit.getMemberName();
-         final RValue initValue = unionInit.getMemberValue();
-
-         Variable memberDef = null;
-         for(Variable definition : memberDefinitions) {
-            if(definition.getLocalName().equals(memberName)) {
-               memberDef = definition;
-            }
-         }
-         if(memberDef==null)
-            throw new CompileError( "Union member not found", source);
-
-         RValue constantifiedMemberValue = constantify(initValue, new ValueTypeSpec(memberDef.getType()), program, source);
-         if(constantifiedMemberValue instanceof ConstantValue) {
-            LinkedHashMap<SymbolVariableRef, ConstantValue> constMemberMap = new LinkedHashMap<>();
+      boolean allConst = true;
+      // Constantified values in a list
+      List<RValue> constantifiedList = new ArrayList<>();
+      // Map filled if all member values become constant
+      LinkedHashMap<SymbolVariableRef, ConstantValue> constMemberMap = new LinkedHashMap<>();
+      Iterator<Variable> memberDefIt = memberDefinitions.iterator();
+      Iterator<RValue> valueIt = valueList.getList().iterator();
+      for(int i = 0; i < structInitNeedSize; i++) {
+         Variable memberDef = memberDefIt.next();
+         RValue memberValue = valueIt.next();
+         RValue constantifiedMemberValue = constantify(memberValue, new ValueTypeSpec(memberDef.getType()), program, source);
+         constantifiedList.add(constantifiedMemberValue);
+         if(constantifiedMemberValue instanceof ConstantValue)
             constMemberMap.put(memberDef.getRef(), (ConstantValue) constantifiedMemberValue);
-            return new ConstantStructValue(structType, constMemberMap);
-         } else {
-            throw new CompileError( "Union initializer is not constant", source);
-         }
+         else
+            allConst = false;
+      }
+      if(allConst) {
+         // Constant struct
+         return new ConstantStructValue(structType, constMemberMap);
       } else {
-         boolean allConst = true;
-         // Constantified values in a list
-         List<RValue> constantifiedList = new ArrayList<>();
-         // Map filled if all member values become constant
-         LinkedHashMap<SymbolVariableRef, ConstantValue> constMemberMap = new LinkedHashMap<>();
-         Iterator<Variable> memberDefIt = memberDefinitions.iterator();
-         Iterator<RValue> valueIt = valueList.getList().iterator();
-         for(int i = 0; i < structInitNeedSize; i++) {
-            Variable memberDef = memberDefIt.next();
-            RValue memberValue = valueIt.next();
-            RValue constantifiedMemberValue = constantify(memberValue, new ValueTypeSpec(memberDef.getType()), program, source);
-            constantifiedList.add(constantifiedMemberValue);
-            if(constantifiedMemberValue instanceof ConstantValue)
-               constMemberMap.put(memberDef.getRef(), (ConstantValue) constantifiedMemberValue);
-            else
-               allConst = false;
-         }
-         if(allConst) {
-            // Constant struct
-            return new ConstantStructValue(structType, constMemberMap);
-         } else {
-            // Constantified list with a cast
-            return new CastValue(structType, new ValueList(constantifiedList));
-         }
-
+         // Constantified list with a cast
+         return new CastValue(structType, new ValueList(constantifiedList));
       }
    }
 
diff --git a/src/main/java/dk/camelot64/kickc/model/values/ValueListUnionDesignator.java b/src/main/java/dk/camelot64/kickc/model/values/UnionDesignator.java
similarity index 53%
rename from src/main/java/dk/camelot64/kickc/model/values/ValueListUnionDesignator.java
rename to src/main/java/dk/camelot64/kickc/model/values/UnionDesignator.java
index ae42ea218..6811766db 100644
--- a/src/main/java/dk/camelot64/kickc/model/values/ValueListUnionDesignator.java
+++ b/src/main/java/dk/camelot64/kickc/model/values/UnionDesignator.java
@@ -2,33 +2,24 @@ package dk.camelot64.kickc.model.values;
 
 import dk.camelot64.kickc.model.Program;
 
-import java.util.ArrayList;
-import java.util.List;
-
 /**
  * A union designator initializer.
- * <p>
- * The init list will have length one.
  */
-public class ValueListUnionDesignator extends ValueList {
+public class UnionDesignator implements RValue {
 
-   private String memberName;
+   private final String memberName;
 
-   public ValueListUnionDesignator(String memberName, RValue rValue) {
-      super(asList(rValue));
+   private final RValue rValue;
+
+   public UnionDesignator(String memberName, RValue rValue) {
       this.memberName = memberName;
-   }
-
-   static List<RValue> asList(RValue rValue) {
-      final ArrayList<RValue> list = new ArrayList<>();
-      list.add(rValue);
-      return list;
+      this.rValue = rValue;
    }
 
    public String getMemberName() { return memberName; }
 
    public RValue getMemberValue() {
-      return getList().get(0);
+      return rValue;
    }
 
    @Override
@@ -37,7 +28,7 @@ public class ValueListUnionDesignator extends ValueList {
       out.append("{ ");
       out.append(memberName);
       out.append("=");
-      out.append(getList().get(0).toString(program));
+      out.append(rValue.toString(program));
       out.append(" }");
       return out.toString();
    }
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
index 4357e149c..3f570bead 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
@@ -1917,7 +1917,7 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
    public RValue visitInitUnion(KickCParser.InitUnionContext ctx) {
       final String memberName = ctx.NAME().getText();
       final RValue rValue = (RValue) visit(ctx.expr());
-      return new ValueListUnionDesignator(memberName, rValue);
+      return new UnionDesignator(memberName, rValue);
    }
 
    @Override