diff --git a/test/tools/ossfuzz/SolProtoAdaptor.cpp b/test/tools/ossfuzz/SolProtoAdaptor.cpp
index 21fdb9446..14fbb4b00 100644
--- a/test/tools/ossfuzz/SolProtoAdaptor.cpp
+++ b/test/tools/ossfuzz/SolProtoAdaptor.cpp
@@ -1182,7 +1182,7 @@ void SolContract::merge()
 			if (holds_alternative<shared_ptr<SolContractFunction>>(f))
 			{
 				auto function = get<shared_ptr<SolContractFunction>>(f);
-				if (function->implemented())
+				if (function->implemented() && (function->visibility() == SolFunctionVisibility::EXTERNAL || function->visibility() == SolFunctionVisibility::PUBLIC))
 					m_contractFunctionMap[name()].insert(pair(function->name(), function->returnValue()));
 			}
 }
@@ -1336,4 +1336,4 @@ pair<string, string> SolLibrary::pseudoRandomTest()
 	}
 	solAssert(m_publicFunctionMap.count(chosenFunction), "Sol proto adaptor: Invalid library function chosen");
 	return pair(chosenFunction, m_publicFunctionMap[chosenFunction]);
-}
\ No newline at end of file
+}