diff --git a/core/src/js/DuktapeContext.h b/core/src/js/DuktapeContext.h
index c31a70210a..bf18faf192 100644
--- a/core/src/js/DuktapeContext.h
+++ b/core/src/js/DuktapeContext.h
@@ -31,7 +31,8 @@
 #define DBG(...)
 #define DUMPCTX(...)
 #endif
-#define DBGCACHE(...) //LOG(__VA_ARGS__)
+#define DBGCACHE(...)
+//#define DBGCACHE(...) LOG(__VA_ARGS__)
 
 namespace Tangram {
 
@@ -608,7 +609,7 @@ struct Context {
         //std::array<uint8_t, SIZE> lengths{};
         std::array<int32_t, SIZE> refs{};
 
-        size_t usage = 0;
+        int usage = 0;
 
         void free(Context& context, const void* ptr) {
             const char* str = (const char*)(ptr);
@@ -628,7 +629,10 @@ struct Context {
         const char* add(Context& context, void* ptr, size_t length) {
             const char* str = (const char*)ptr;
             int slot = -1;
-            for (size_t i = 0; i < usage; i++) {
+            for (int i = 0; i < usage; i++) {
+                DBGCACHE("[%d/%d]", i, usage);
+                assert(int64_t(ENTRIES) - int64_t(i) > 0);
+
                 if (length <= strings[i][0] && std::memcmp(&strings[i][1], str, length) == 0) {
                     refs[i]++;
                     DBGCACHE("[%d] found '%.*s'", refs[i], length, &strings[i][stroffset]);
@@ -639,9 +643,8 @@ struct Context {
                 }
             }
             if (slot == -1) {
-                if (usage < strings.size()) {
-                    slot = usage;
-                    usage++;
+                if (usage < ENTRIES) {
+                    slot = usage++;
                 } else {
                     LOG("cache full: %.*s len:%d - usage:%d, slot:%d", length, str, length, usage, slot);
                     return nullptr;
@@ -655,7 +658,7 @@ struct Context {
 
             context._allocCnt++;
 
-            DBGCACHE("[%d] added: '%.*s'", refs[slot], length, out);
+            DBGCACHE("[%d] added: '%.*s'", refs[slot], length, str);
 
             return &strings[slot][stroffset];
         }