diff --git a/ast.cpp b/ast.cpp
index d858c371..097439bd 100644
--- a/ast.cpp
+++ b/ast.cpp
@@ -58,7 +58,14 @@ void
 AST::AddFunction(Symbol *sym, Stmt *code) {
     if (sym == NULL)
         return;
-    functions.push_back(new Function(sym, code));
+
+    Function *f = new Function(sym, code);
+
+    if (f->IsPolyFunction()) {
+        FATAL("This is a good start, but implement me!");
+    } else {
+        functions.push_back(f);
+    }
 }
 
 
diff --git a/func.cpp b/func.cpp
index 925bbc2b..0d68fb5e 100644
--- a/func.cpp
+++ b/func.cpp
@@ -627,3 +627,14 @@ Function::GenerateIR() {
         }
     }
 }
+
+const bool
+Function::IsPolyFunction() const {
+    for (size_t i = 0; i < args.size(); i++) {
+        if (args[i]->type->IsPolymorphicType()) {
+            return true;
+        }
+    }
+
+    return false;
+}
diff --git a/func.h b/func.h
index 3019eeb1..94f012a7 100644
--- a/func.h
+++ b/func.h
@@ -51,6 +51,9 @@ public:
     /** Generate LLVM IR for the function into the current module. */
     void GenerateIR();
 
+    /** Checks if the function has polymorphic parameters */
+    const bool IsPolyFunction() const;
+
 private:
     void emitCode(FunctionEmitContext *ctx, llvm::Function *function,
                   SourcePos firstStmtPos);
diff --git a/type.cpp b/type.cpp
index 9078b1fb..8450ee23 100644
--- a/type.cpp
+++ b/type.cpp
@@ -247,6 +247,11 @@ Type::IsVoidType() const {
     return EqualIgnoringConst(this, AtomicType::Void);
 }
 
+bool
+Type::IsPolymorphicType() const {
+    return (CastType<PolyType>(GetBaseType()) != NULL);
+}
+
 bool
 AtomicType::IsFloatType() const {
     return (basicType == TYPE_FLOAT || basicType == TYPE_DOUBLE);
diff --git a/type.h b/type.h
index 7f2fc9bd..07831e01 100644
--- a/type.h
+++ b/type.h
@@ -133,6 +133,9 @@ public:
     /** Returns true if the underlying type is either a pointer or an array */
     bool IsVoidType() const;
 
+    /** Returns true if the underlying type is polymorphic */
+    bool IsPolymorphicType() const;
+
     /** Returns true if this type is 'const'-qualified. */
     virtual bool IsConstType() const = 0;