diff --git a/ddprof-lib/src/main/cpp/context.cpp b/ddprof-lib/src/main/cpp/context.cpp
index f65eb0d08..f135de84c 100644
--- a/ddprof-lib/src/main/cpp/context.cpp
+++ b/ddprof-lib/src/main/cpp/context.cpp
@@ -35,6 +35,9 @@ Context& Contexts::get(int tid) {
             if ((context.spanId ^ context.rootSpanId) == context.checksum) {
                 return context;
             }
+            Counters::increment(CounterId::CONTEXT_CHECKSUM_REJECT_GETS);
+        } else {
+            Counters::increment(CounterId::CONTEXT_NULL_PAGE_GETS);
         }
     } else {
         Counters::increment(CounterId::CONTEXT_BOUNDS_MISS_GETS);
diff --git a/ddprof-lib/src/main/cpp/counters.h b/ddprof-lib/src/main/cpp/counters.h
index 133aadc0e..5c2c58152 100644
--- a/ddprof-lib/src/main/cpp/counters.h
+++ b/ddprof-lib/src/main/cpp/counters.h
@@ -41,6 +41,8 @@
     X(CONTEXT_STORAGE_PAGES, "context_storage_pages")       \
     X(CONTEXT_BOUNDS_MISS_INITS, "context_bounds_miss_inits")   \
     X(CONTEXT_BOUNDS_MISS_GETS, "context_bounds_miss_gets") \
+    X(CONTEXT_CHECKSUM_REJECT_GETS, "context_checksum_reject_gets") \
+    X(CONTEXT_NULL_PAGE_GETS, "context_null_page_gets") \
     X(CALLTRACE_STORAGE_BYTES, "calltrace_storage_bytes") \
     X(CALLTRACE_STORAGE_TRACES, "calltrace_storage_traces") \
     X(LINEAR_ALLOCATOR_BYTES, "linear_allocator_bytes") \