diff --git a/pkgs/development/compilers/ghdl/default.nix b/pkgs/development/compilers/ghdl/default.nix
index 6181486f50c7..e73324394394 100644
--- a/pkgs/development/compilers/ghdl/default.nix
+++ b/pkgs/development/compilers/ghdl/default.nix
@@ -5,24 +5,22 @@ assert backend == "mcode" || backend == "llvm";
 
 stdenv.mkDerivation rec {
   pname = "ghdl-${backend}";
-  # NOTE(aseipp): move to 0.38 when it comes out, since it should support a stable
-  # version of the yosys plugin
-  version = "unstable-2021.01.14";
+  version = "1.0.0";
 
   src = fetchFromGitHub {
     owner  = "ghdl";
     repo   = "ghdl";
-    rev    = "4868294436574660552ccef50a5b0849559393de";
-    sha256 = "1wqjf0qc66dam1n2mskmlvj53bcsdwwk5rq9gimq6ah1vcwi222p";
+    rev    = "v${version}";
+    sha256 = "1gyh0xckwbzgslbpw9yrpj4gqs9fm1a2qpbzl0sh143fk1kwjlly";
   };
 
   LIBRARY_PATH = "${stdenv.cc.libc}/lib";
 
-  buildInputs = [ gnat zlib ];
+  buildInputs = [ gnat zlib ] ++ lib.optional (backend == "llvm") [ llvm ];
 
   preConfigure = ''
     # If llvm 7.0 works, 7.x releases should work too.
-    sed -i 's/check_version 7.0/check_version 7/g' configure
+    sed -i 's/check_version  7.0/check_version  7/g' configure
   '';
 
   configureFlags = [ "--enable-synth" ] ++ lib.optional (backend == "llvm")
diff --git a/pkgs/development/compilers/yosys/plugins/ghdl.nix b/pkgs/development/compilers/yosys/plugins/ghdl.nix
index ccf8efc7c805..35f3ef2bcc88 100644
--- a/pkgs/development/compilers/yosys/plugins/ghdl.nix
+++ b/pkgs/development/compilers/yosys/plugins/ghdl.nix
@@ -4,13 +4,13 @@
 
 stdenv.mkDerivation {
   pname = "yosys-ghdl";
-  version = "2021.01.01";
+  version = "2021.01.25";
 
   src = fetchFromGitHub {
     owner  = "ghdl";
     repo   = "ghdl-yosys-plugin";
-    rev    = "8b3e740fef9a653a20a838f1ade475960e1d379b";
-    sha256 = "13kpcp37r11xgqd8aksddi40a5vpzqi7p8qgyjbs99lyscyli75x";
+    rev    = "cba859cacf8c6631146dbdaa0f297c060b5a68cd";
+    sha256 = "01d9wb7sqkmkf2y9bnn3pmhy08khzs5m1d06whxsiwgwnjzfk9mx";
   };
 
   buildInputs = [ yosys readline zlib ghdl ];