diff --git a/CHANGES.md b/CHANGES.md
index efa2b13..aa0f878 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,4 +1,8 @@
-## 5.1.0 (2021-09-22)
+### Pending
+
+- Don't use `-lpthread` and non-MSVC flags with MSVC compiler
+
+### 5.1.0 (2021-09-22)
 
 - Added let&-operator for implicit closing of an opened database.
 
diff --git a/src/config/discover.ml b/src/config/discover.ml
index 99db6a9..ceb7ffb 100644
--- a/src/config/discover.ml
+++ b/src/config/discover.ml
@@ -68,6 +68,16 @@ let split_ws str =
   done;
   List.rev !lst
 
+let add_compiler_args ~is_msvc ~cflags ~libs =
+  let module C = Configurator.V1 in
+  match is_msvc with
+  | true -> { C.Pkg_config.cflags = cflags @ [ "/O2" ]; libs }
+  | false ->
+      {
+        C.Pkg_config.cflags = cflags @ [ "-O2"; "-fPIC"; "-DPIC" ];
+        libs = libs @ [ "-lpthread" ];
+      }
+
 let () =
   let module C = Configurator.V1 in
   C.main ~name:"sqlite3" (fun c ->
@@ -76,6 +86,11 @@ let () =
           | "macosx" -> true
           | _ -> false)
       in
+      let is_msvc =
+        opt_map (C.ocaml_config_var c "ccomp_type") ~default:false ~f:(function
+          | "msvc" -> true
+          | _ -> false)
+      in
       let is_mingw =
         opt_map (C.ocaml_config_var c "system") ~default:false ~f:(function
           | "mingw" | "mingw64" -> true
@@ -111,6 +126,6 @@ let () =
         | [ libs ] -> split_ws libs
         | _ -> failwith "pkg-config failed to return libs"
       in
-      let conf = { C.Pkg_config.cflags; libs } in
+      let conf = add_compiler_args ~is_msvc ~cflags ~libs in
       C.Flags.write_sexp "c_flags.sexp" conf.cflags;
       C.Flags.write_sexp "c_library_flags.sexp" conf.libs)
diff --git a/src/dune b/src/dune
index dac3b8f..e3d72a9 100644
--- a/src/dune
+++ b/src/dune
@@ -5,10 +5,7 @@
   (names sqlite3_stubs)
   (flags
    (:standard)
-   (:include c_flags.sexp)
-   -O2
-   -fPIC
-   -DPIC))
+   (:include c_flags.sexp)))
  (c_library_flags
   (:include c_library_flags.sexp)))