diff --git a/src/H5FL.c b/src/H5FL.c
index db35a0817c2..21017c93b6e 100644
--- a/src/H5FL.c
+++ b/src/H5FL.c
@@ -74,7 +74,7 @@
  *  Default limits on how much memory can accumulate on each free list before
  *  it is garbage collected.
  */
-#ifdef H5_HAVE_CONCURRENCY
+#ifdef H5_HAVE_THREADS
 static bool               H5TS_limits_init = false;
 static H5TS_atomic_size_t H5FL_reg_glb_mem_lim;
 static H5TS_atomic_size_t H5FL_reg_lst_mem_lim;
@@ -84,7 +84,7 @@ static H5TS_atomic_size_t H5FL_blk_glb_mem_lim;
 static H5TS_atomic_size_t H5FL_blk_lst_mem_lim;
 static H5TS_atomic_size_t H5FL_fac_glb_mem_lim;
 static H5TS_atomic_size_t H5FL_fac_lst_mem_lim;
-#else  /* H5_HAVE_CONCURRENCY */
+#else  /* H5_HAVE_THREADS */
 static size_t H5FL_reg_glb_mem_lim = H5FL_REG_GLB_MEM_LIM;
 static size_t H5FL_reg_lst_mem_lim = H5FL_REG_LST_MEM_LIM;
 static size_t H5FL_arr_glb_mem_lim = H5FL_ARR_GLB_MEM_LIM;
@@ -93,7 +93,7 @@ static size_t H5FL_blk_glb_mem_lim = H5FL_BLK_GLB_MEM_LIM;
 static size_t H5FL_blk_lst_mem_lim = H5FL_BLK_LST_MEM_LIM;
 static size_t H5FL_fac_glb_mem_lim = H5FL_FAC_GLB_MEM_LIM;
 static size_t H5FL_fac_lst_mem_lim = H5FL_FAC_LST_MEM_LIM;
-#endif /* H5_HAVE_CONCURRENCY */
+#endif /* H5_HAVE_THREADS */
 
 /* A garbage collection node for regular free lists */
 typedef struct H5FL_reg_gc_node_t {
@@ -145,7 +145,7 @@ typedef struct H5FL_blk_gc_list_t {
     bool               init;              /* Whether the mutex has been initialized */
     H5TS_dlftt_mutex_t mutex;             /* Guard access to the list of free lists */
 #endif                                    /* H5_HAVE_CONCURRENCY */
-    size_t                     mem_freed; /* Amount of free memory on list */
+    H5TS_atomic_size_t mem_freed; /* Amount of free memory on list */
     struct H5FL_blk_gc_node_t *first; /* Pointer to the first node in the list of things to garbage collect */
 } H5FL_blk_gc_list_t;