diff --git a/src/typechecker/typechecker.cpp b/src/typechecker/typechecker.cpp
index 56d1d5f..4117abd 100644
--- a/src/typechecker/typechecker.cpp
+++ b/src/typechecker/typechecker.cpp
@@ -308,12 +308,13 @@ namespace Solstice {
                 break;
             }
             case Narrowing::None: {
-                for (const auto& [key, value] : overloads) {
-                    if (
-                        left.ptype.possiblities.find(key.left) != left.ptype.possiblities.end() &&
-                        right.ptype.possiblities.find(key.right) != right.ptype.possiblities.end()
-                    )  {
-                        node.ptype.possiblities.insert(value);
+                for (const auto& ltype : left.ptype.possiblities) {
+                    for (const auto& rtype : right.ptype.possiblities) {
+                        TypePair pair{ltype, rtype};
+                        if (overloads.find(pair) == overloads.end()) {
+                            throw std::runtime_error("no valid overload compatible with previous statements");
+                        } 
+                        node.ptype.possiblities.insert(overloads[pair]);
                     }
                 }
                 break;