diff --git a/derive_builder_core-fix-metadata.diff b/derive_builder_core-fix-metadata.diff
new file mode 100644
index 0000000..96739aa
--- /dev/null
+++ b/derive_builder_core-fix-metadata.diff
@@ -0,0 +1,11 @@
+--- derive_builder_core-0.9.0/Cargo.toml	2019-11-07T20:52:44+00:00
++++ derive_builder_core-0.9.0/Cargo.toml	2021-02-27T20:26:31.888507+00:00
+@@ -20,7 +20,7 @@
+ license = "MIT/Apache-2.0"
+ repository = "https://github.com/colin-kiegel/rust-derive-builder"
+ [dependencies.darling]
+-version = "0.10.2"
++version = "0.12"
+ 
+ [dependencies.log]
+ version = "0.4"
diff --git a/rust-derive_builder_core.spec b/rust-derive_builder_core.spec
index 96a6aa6..eb8bcb1 100644
--- a/rust-derive_builder_core.spec
+++ b/rust-derive_builder_core.spec
@@ -1,4 +1,4 @@
-# Generated by rust2rpm 11
+# Generated by rust2rpm 16
 %bcond_without check
 %global debug_package %{nil}
 
@@ -6,13 +6,17 @@
 
 Name:           rust-%{crate}
 Version:        0.9.0
-Release:        5%{?dist}
+Release:        6%{?dist}
 Summary:        Internal helper library for the derive_builder crate
 
 # Upstream license specification: MIT/Apache-2.0
 License:        MIT or ASL 2.0
 URL:            https://crates.io/crates/derive_builder_core
 Source:         %{crates_source}
+# Initial patched metadata
+# * bump to darling 0.12 (already upstream):
+#   https://github.com/colin-kiegel/rust-derive-builder/commit/ee13c51
+Patch0:         derive_builder_core-fix-metadata.diff
 
 ExclusiveArch:  %{rust_arches}
 %if %{__cargo_skip_build}
@@ -38,7 +42,7 @@ which use "%{crate}" crate.
 %files          devel
 %license LICENSE-MIT LICENSE-APACHE
 %doc README.md CHANGELOG.md
-%{cargo_registry}/%{crate}-%{version}/
+%{cargo_registry}/%{crate}-%{version_no_tilde}/
 
 %package     -n %{name}+default-devel
 Summary:        %{summary}
@@ -50,7 +54,7 @@ This package contains library source intended for building other packages
 which use "default" feature of "%{crate}" crate.
 
 %files       -n %{name}+default-devel
-%ghost %{cargo_registry}/%{crate}-%{version}/Cargo.toml
+%ghost %{cargo_registry}/%{crate}-%{version_no_tilde}/Cargo.toml
 
 %package     -n %{name}+log-devel
 Summary:        %{summary}
@@ -62,7 +66,7 @@ This package contains library source intended for building other packages
 which use "log" feature of "%{crate}" crate.
 
 %files       -n %{name}+log-devel
-%ghost %{cargo_registry}/%{crate}-%{version}/Cargo.toml
+%ghost %{cargo_registry}/%{crate}-%{version_no_tilde}/Cargo.toml
 
 %package     -n %{name}+logging-devel
 Summary:        %{summary}
@@ -74,7 +78,7 @@ This package contains library source intended for building other packages
 which use "logging" feature of "%{crate}" crate.
 
 %files       -n %{name}+logging-devel
-%ghost %{cargo_registry}/%{crate}-%{version}/Cargo.toml
+%ghost %{cargo_registry}/%{crate}-%{version_no_tilde}/Cargo.toml
 
 %prep
 %autosetup -n %{crate}-%{version_no_tilde} -p1
@@ -95,6 +99,9 @@ which use "logging" feature of "%{crate}" crate.
 %endif
 
 %changelog
+* Sat Feb 27 2021 Fabio Valentini <decathorpe@gmail.com> - 0.9.0-6
+- Bump to darling 0.12.
+
 * Wed Jan 27 2021 Fedora Release Engineering <releng@fedoraproject.org> - 0.9.0-5
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild