diff --git a/src/parser/JaniParser.cpp b/src/parser/JaniParser.cpp
index 7f7ee03fc..bf03db99d 100644
--- a/src/parser/JaniParser.cpp
+++ b/src/parser/JaniParser.cpp
@@ -56,7 +56,7 @@ namespace storm {
         }
 
         std::shared_ptr<storm::jani::Composition> JaniParser::parseComposition(json const &compositionStructure) {
-            
+
         }
     }
 }
\ No newline at end of file
diff --git a/src/storage/jani/Model.cpp b/src/storage/jani/Model.cpp
index 337dd7c39..f3ffb108a 100644
--- a/src/storage/jani/Model.cpp
+++ b/src/storage/jani/Model.cpp
@@ -6,9 +6,31 @@ namespace storm {
         Model::Model(ModelType const& modelType, uint64_t version) : modelType(modelType), version(version) {
             // Intentionally left empty.
         }
-        
-        bool Model::isValid(bool logDebug) const {
-            // TODO.
+
+        void Model::checkSupported() {
+            //TODO
+        }
+
+        bool Model::checkValidity(bool logdbg) {
+            // TODO switch to exception based return value.
+
+            if (version == 0) {
+                if(logdbg) STORM_LOG_DEBUG("Jani version is unspecified");
+                return false;
+            }
+
+            if(modelType == ModelType::UNDEFINED) {
+                if(logdbg) STORM_LOG_DEBUG("Model type is unspecified");
+                return false;
+            }
+
+            if(automata.empty()) {
+                if(logdbg) STORM_LOG_DEBUG("No automata specified");
+                return false;
+            }
+            // All checks passed.
+            return true;
+
         }
         
     }