diff --git a/include/sta/ClkInfo.hh b/include/sta/ClkInfo.hh
index 97bd678f..afbbdb1b 100644
--- a/include/sta/ClkInfo.hh
+++ b/include/sta/ClkInfo.hh
@@ -83,9 +83,9 @@ private:
   Arrival insertion_;
   float latency_;
   size_t hash_;
-  unsigned int is_propagated_:1;
-  unsigned int is_gen_clk_src_path_:1;
-  unsigned int is_pulse_clk_:1;
+  bool is_propagated_:1;
+  bool is_gen_clk_src_path_:1;
+  bool is_pulse_clk_:1;
   unsigned int pulse_clk_sense_:RiseFall::index_bit_count;
   unsigned int path_ap_index_:path_ap_index_bit_count;
 };
diff --git a/search/TagGroup.hh b/search/TagGroup.hh
index c0cffac6..8422d34d 100644
--- a/search/TagGroup.hh
+++ b/search/TagGroup.hh
@@ -71,11 +71,11 @@ protected:
   ArrivalMap *arrival_map_;
   size_t hash_;
   unsigned int index_:tag_group_index_bits;
-  unsigned int has_clk_tag_:1;
-  unsigned int has_genclk_src_tag_:1;
-  unsigned int has_filter_tag_:1;
-  unsigned int has_loop_tag_:1;
-  unsigned int own_arrival_map_:1;
+  bool has_clk_tag_:1;
+  bool has_genclk_src_tag_:1;
+  bool has_filter_tag_:1;
+  bool has_loop_tag_:1;
+  bool own_arrival_map_:1;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(TagGroup);