diff --git a/pkgs/development/libraries/tdb/default.nix b/pkgs/development/libraries/tdb/default.nix
index 4a0c8a6cad08..c166d36d5a60 100644
--- a/pkgs/development/libraries/tdb/default.nix
+++ b/pkgs/development/libraries/tdb/default.nix
@@ -16,7 +16,7 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "mirror://samba/tdb/${pname}-${version}.tar.gz";
-    sha256 = "sha256-hDTJyFfRPOP6hGb3VgHyXDaTZ2s2kZ8VngrWEhuvXOg=";
+    hash = "sha256-hDTJyFfRPOP6hGb3VgHyXDaTZ2s2kZ8VngrWEhuvXOg=";
   };
 
   nativeBuildInputs = [
@@ -48,6 +48,10 @@ stdenv.mkDerivation rec {
     "--builtin-libraries=replace"
   ];
 
+  postFixup = if stdenv.isDarwin
+    then ''install_name_tool -id $out/lib/libtdb.dylib $out/lib/libtdb.dylib''
+    else null;
+
   # python-config from build Python gives incorrect values when cross-compiling.
   # If python-config is not found, the build falls back to using the sysconfig
   # module, which works correctly in all cases.
diff --git a/pkgs/tools/networking/fdm/default.nix b/pkgs/tools/networking/fdm/default.nix
index 731fe83dc9bc..7ef5cf0b4edd 100644
--- a/pkgs/tools/networking/fdm/default.nix
+++ b/pkgs/tools/networking/fdm/default.nix
@@ -8,17 +8,16 @@ stdenv.mkDerivation rec {
     owner = "nicm";
     repo = pname;
     rev = version;
-    sha256 = "sha256-Gqpz+N1ELU5jQpPJAG9s8J9UHWOJNhkT+s7+xuQazd0=";
+    hash = "sha256-Gqpz+N1ELU5jQpPJAG9s8J9UHWOJNhkT+s7+xuQazd0=";
   };
 
   nativeBuildInputs = [ autoreconfHook ];
   buildInputs = [ openssl tdb zlib flex bison ];
 
-
   meta = with lib; {
     description = "Mail fetching and delivery tool - should do the job of getmail and procmail";
     maintainers = with maintainers; [ raskin ];
-    platforms = with platforms; linux;
+    platforms = with platforms; linux ++ darwin;
     homepage = "https://github.com/nicm/fdm";
     downloadPage = "https://github.com/nicm/fdm/releases";
     license = licenses.isc;