diff --git a/src/env.c b/src/env.c
index 59e941a..1be57da 100644
--- a/src/env.c
+++ b/src/env.c
@@ -191,11 +191,11 @@ struct Environment defaultEnv()
         {"at", &at}, {"rest", &rest}, {"rev", &reverse},
     };
 
-    for(int i = 0; i < sizeof(symFuncs)/sizeof(symFuncs[0]); i++) {
+    for(unsigned i = 0; i < sizeof(symFuncs)/sizeof(symFuncs[0]); i++) {
         addFunc(symFuncs[i].sym, symFuncs[i].func, &e);
     }
 
-    for(int i = 0; i < sizeof(codes)/sizeof(codes[0]); i++) {
+    for(unsigned i = 0; i < sizeof(codes)/sizeof(codes[0]); i++) {
         parseEval(codes[i], &e);
     }