diff --git a/src/collections.h b/src/collections.h
index 0ff39fe4..9008dce7 100644
--- a/src/collections.h
+++ b/src/collections.h
@@ -24,6 +24,7 @@ KHASH_INIT(char_uint32, char, uint32_t, 1, kh_char_hash_func, kh_char_hash_equal
 KHASH_INIT(uchar_uint32, unsigned char, uint32_t, 1, kh_char_hash_func, kh_char_hash_equal)
 
 KHASH_MAP_INIT_STR(str_uint32, uint32_t)
+KHASH_MAP_INIT_STR(str_double, double)
 KHASH_MAP_INIT_INT(int_str, char *)
 KHASH_MAP_INIT_STR(str_str, char *)
 
diff --git a/src/features.c b/src/features.c
index d0375888..782a5996 100644
--- a/src/features.c
+++ b/src/features.c
@@ -26,18 +26,29 @@ void feature_array_add_printf(cstring_array *features, char *format, ...) {
 }
 
 
-bool feature_counts_update(khash_t(str_uint32) *features, char *feature, int count) {
+bool feature_counts_update_or_add(khash_t(str_double) *features, char *feature, double count, bool add) {
     khiter_t k;
 
-    k = kh_get(str_uint32, features, feature);
+    k = kh_get(str_double, features, feature);
     if (k == kh_end(features)) {
         int ret;
-        k = kh_put(str_uint32, features, feature, &ret);
+        k = kh_put(str_double, features, feature, &ret);
         if (ret < 0) return false;
 
         kh_value(features, k) = count;
-    } else {
+    } else if (add) {
         kh_value(features, k) += count;
+    } else {
+        kh_value(features, k) = count;
     }
     return true;
 }
+
+
+inline bool feature_counts_add(khash_t(str_double) *features, char *feature, double count) {
+    return feature_counts_update_or_add(features, feature, count, true);
+}
+
+inline bool feature_counts_update(khash_t(str_double) *features, char *feature, double count) {
+    return feature_counts_update_or_add(features, feature, count, false);
+}
diff --git a/src/features.h b/src/features.h
index d67d9ce5..97fbb3ec 100644
--- a/src/features.h
+++ b/src/features.h
@@ -17,6 +17,9 @@ void feature_array_add_printf(cstring_array *features, char *format, ...);
 
 // Add feature count to dictionary
 
-bool feature_counts_update(khash_t(str_uint32) *features, char *feature, int count); 
+bool feature_counts_add(khash_t(str_double) *features, char *feature, double count); 
+bool feature_counts_update(khash_t(str_double) *features, char *feature, double count); 
+
+VECTOR_INIT(feature_count_array, khash_t(str_double) *)
 
 #endif
\ No newline at end of file