diff --git a/gen/api_defs.jl b/gen/api_defs.jl
index c0c3f93f9..0aaeaf65f 100644
--- a/gen/api_defs.jl
+++ b/gen/api_defs.jl
@@ -27,7 +27,7 @@
 @bind h5_free_memory(buf::Ptr{Cvoid})::herr_t "Error freeing memory"
 @bind h5_garbage_collect()::herr_t "Error on garbage collect"
 @bind h5_get_libversion(majnum::Ref{Cuint}, minnum::Ref{Cuint}, relnum::Ref{Cuint})::herr_t "Error getting HDF5 library version"
-@bind h5_is_library_threadsafe(is_ts::Ref{Cuint})::herr_t "Error determining thread safety"
+@bind h5_is_library_threadsafe(is_ts::Ref{Cuchar})::herr_t "Error determining thread safety"
 @bind h5_open()::herr_t "Error initializing the HDF5 library"
 @bind h5_set_free_list_limits(reg_global_lim::Cint, reg_list_lim::Cint, arr_global_lim::Cint, arr_list_lim::Cint, blk_global_lim::Cint, blk_list_lim::Cint)::herr_t "Error setting limits on free lists"
 
diff --git a/src/api/functions.jl b/src/api/functions.jl
index 311b4651c..46f5adee0 100644
--- a/src/api/functions.jl
+++ b/src/api/functions.jl
@@ -92,14 +92,14 @@ function h5_get_libversion(majnum, minnum, relnum)
 end
 
 """
-    h5_is_library_threadsafe(is_ts::Ref{Cuint})
+    h5_is_library_threadsafe(is_ts::Ref{Cuchar})
 
 See `libhdf5` documentation for [`H5is_library_threadsafe`](https://docs.hdfgroup.org/hdf5/v1_14/group___h5.html#ga70bfde4acd009cdd7bcd2f54c594e28a).
 """
 function h5_is_library_threadsafe(is_ts)
     lock(liblock)
     var"#status#" = try
-            ccall((:H5is_library_threadsafe, libhdf5), herr_t, (Ref{Cuint},), is_ts)
+            ccall((:H5is_library_threadsafe, libhdf5), herr_t, (Ref{Cuchar},), is_ts)
         finally
             unlock(liblock)
         end
diff --git a/src/api/helpers.jl b/src/api/helpers.jl
index f77cb26da..1b0fdb117 100644
--- a/src/api/helpers.jl
+++ b/src/api/helpers.jl
@@ -26,7 +26,7 @@ function h5_get_libversion()
 end
 
 function h5_is_library_threadsafe()
-    is_ts = Ref{Cuint}()
+    is_ts = Ref{Cuchar}(0)
     h5_is_library_threadsafe(is_ts)
     return is_ts[] > 0
 end