diff --git a/lib/codegen/fromcto/avro/avrovisitor.js b/lib/codegen/fromcto/avro/avrovisitor.js
index d44ce0cd..a17f13eb 100644
--- a/lib/codegen/fromcto/avro/avrovisitor.js
+++ b/lib/codegen/fromcto/avro/avrovisitor.js
@@ -181,6 +181,22 @@ class AvroVisitor {
             avroType = `union { null, ${avroType} }`;
         }
 
+        if (ModelUtil.isMap(field)) {
+            const mapDeclaration = field.getModelFile().getType(field.getType());
+            let mapValueType = mapDeclaration.getValue().getType();
+
+            if (ModelUtil.isScalar(mapDeclaration.getValue())) {
+                const scalarDeclaration = mapDeclaration.getModelFile().getType(mapValueType);
+                mapValueType = scalarDeclaration.getType();
+            }
+
+            const avroValueType = this.toAvroType(mapValueType);
+
+            parameters.fileWriter.writeLine(2, `map<${avroValueType}> ${field.getName()};`); // key is always inferred to be string.
+
+            return null;
+        }
+
         const fieldName = this.toAvroName(field.getName());
 
         /**
diff --git a/test/codegen/__snapshots__/codegen.js.snap b/test/codegen/__snapshots__/codegen.js.snap
index dd92e2f9..2b0b19ea 100644
--- a/test/codegen/__snapshots__/codegen.js.snap
+++ b/test/codegen/__snapshots__/codegen.js.snap
@@ -110,11 +110,11 @@ protocol MyProtocol {
    record Company {
       string name;
       Address headquarters;
-      union { null, CompanyProperties } companyProperties;
-      union { null, EmployeeDirectory } employeeDirectory;
-      union { null, EmployeeTShirtSizes } employeeTShirtSizes;
-      union { null, EmployeeProfiles } employeeProfiles;
-      union { null, EmployeeSocialSecurityNumbers } employeeSocialSecurityNumbers;
+      map<string> companyProperties;
+      map<Employee> employeeDirectory;
+      map<TShirtSizeType> employeeTShirtSizes;
+      map<Concept> employeeProfiles;
+      map<string> employeeSocialSecurityNumbers;
    }
 
    enum Department {
@@ -150,7 +150,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record Employee {
@@ -171,7 +171,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record Contractor {
@@ -186,7 +186,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record Manager {
@@ -208,7 +208,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record CompanyEvent {
@@ -6012,11 +6012,11 @@ protocol MyProtocol {
    record Company {
       string name;
       Address headquarters;
-      union { null, CompanyProperties } companyProperties;
-      union { null, EmployeeDirectory } employeeDirectory;
-      union { null, EmployeeTShirtSizes } employeeTShirtSizes;
-      union { null, EmployeeProfiles } employeeProfiles;
-      union { null, EmployeeSocialSecurityNumbers } employeeSocialSecurityNumbers;
+      map<string> companyProperties;
+      map<Employee> employeeDirectory;
+      map<TShirtSizeType> employeeTShirtSizes;
+      map<Concept> employeeProfiles;
+      map<string> employeeSocialSecurityNumbers;
    }
 
    enum Department {
@@ -6052,7 +6052,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record Employee {
@@ -6073,7 +6073,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record Contractor {
@@ -6088,7 +6088,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record Manager {
@@ -6110,7 +6110,7 @@ protocol MyProtocol {
       double height;
       @logicalType("timestamp-micros")
       long dob;
-      NextOfKin nextOfKin;
+      map<string> nextOfKin;
    }
 
    record CompanyEvent {