diff --git a/profile.sh b/profile.sh
index 38835cce..80e9ff2c 100644
--- a/profile.sh
+++ b/profile.sh
@@ -1,6 +1,6 @@
 g++ -o pocketpy src/main.cpp --std=c++17 -pg -O2 -fno-rtti
 
-./pocketpy benchmarks/fib.py
+./pocketpy benchmarks/primes.py
 
 gprof pocketpy gmon.out > gprof.txt
 
diff --git a/src/codeobject.h b/src/codeobject.h
index a6da1833..a5175a9b 100644
--- a/src/codeobject.h
+++ b/src/codeobject.h
@@ -66,7 +66,7 @@ struct CodeObject {
     std::map<StrName, int> labels;
 
     uint32_t perfect_locals_capacity = 2;
-    uint32_t perfect_hash_seed = 0xffffffff;
+    uint32_t perfect_hash_seed = -1;
 
     void optimize(VM* vm);
 
diff --git a/src/namedict.h b/src/namedict.h
index becabe59..2c8faac3 100644
--- a/src/namedict.h
+++ b/src/namedict.h
@@ -20,7 +20,7 @@ namespace pkpy{
     }
 
     uint32_t find_perfect_hash_seed(uint32_t capacity, const std::vector<StrName>& keys){
-        if(keys.empty()) return 0xffffffff;
+        if(keys.empty()) return -1;
         std::set<uint32_t> indices;
         std::vector<std::pair<uint32_t, float>> scores;
         for(int i=0; i<kHashSeeds.size(); i++){
@@ -49,7 +49,7 @@ namespace pkpy{
         uint32_t _hash_seed;
         NameDictNode* _a;
 
-        NameDict(uint32_t capacity=2, float load_factor=0.67, uint32_t hash_seed=0xffffffff):
+        NameDict(uint32_t capacity=2, float load_factor=0.67, uint32_t hash_seed=-1):
             _capacity(capacity), _size(0), _load_factor(load_factor),
             _hash_seed(hash_seed), _a(new NameDictNode[capacity]) {}