diff --git a/src/libexpr/eval-settings.hh b/src/libexpr/eval-settings.hh
index a8fcce539..fe947aefd 100644
--- a/src/libexpr/eval-settings.hh
+++ b/src/libexpr/eval-settings.hh
@@ -2,7 +2,6 @@
 ///@file
 
 #include "config.hh"
-#include "ref.hh"
 #include "source-path.hh"
 
 namespace nix {
diff --git a/src/libfetchers/meson.build b/src/libfetchers/meson.build
index ac69ab8dc..fa5286ce9 100644
--- a/src/libfetchers/meson.build
+++ b/src/libfetchers/meson.build
@@ -14,7 +14,7 @@ cxx = meson.get_compiler('cpp')
 
 subdir('nix-meson-build-support/deps-lists')
 
-configdata = configuration_data()
+configuration_data()
 
 deps_private_maybe_subproject = [
 ]
diff --git a/src/libutil/file-descriptor.cc b/src/libutil/file-descriptor.cc
index 542c33f3b..707c0f882 100644
--- a/src/libutil/file-descriptor.cc
+++ b/src/libutil/file-descriptor.cc
@@ -1,6 +1,3 @@
-#include "file-system.hh"
-#include "signals.hh"
-#include "finally.hh"
 #include "serialise.hh"
 #include "util.hh"
 
diff --git a/src/nix/meson.build b/src/nix/meson.build
index 2698cc873..976ff1489 100644
--- a/src/nix/meson.build
+++ b/src/nix/meson.build
@@ -223,7 +223,7 @@ foreach linkname : nix_symlinks
     # The 'runtime' tag is what executables default to, which we want to emulate here.
     install_tag : 'runtime'
   )
-  t = custom_target(
+  custom_target(
     command: ['ln', '-sf', fs.name(this_exe), '@OUTPUT@'],
     output: linkname + executable_suffix,
     # native doesn't allow dangling symlinks, but the target executable often doesn't exist at this time
diff --git a/src/perl/meson.build b/src/perl/meson.build
index 7b3716c17..599e91710 100644
--- a/src/perl/meson.build
+++ b/src/perl/meson.build
@@ -57,10 +57,10 @@ libdir = join_paths(prefix, get_option('libdir'))
 
 # Required Programs
 #-------------------------------------------------
-xz = find_program('xz')
+find_program('xz')
 xsubpp = find_program('xsubpp')
 perl = find_program('perl')
-curl = find_program('curl')
+find_program('curl')
 yath = find_program('yath', required : false)
 
 # Required Libraries
@@ -157,7 +157,7 @@ subdir(lib_dir)
 if get_option('tests').enabled()
   yath_rc_conf = configuration_data()
   yath_rc_conf.set('lib_dir', lib_dir)
-  yath_rc = configure_file(
+  configure_file(
     output : '.yath.rc',
     input : '.yath.rc.in',
     configuration : yath_rc_conf,
diff --git a/tests/functional/meson.build b/tests/functional/meson.build
index 3342ee870..af95879fb 100644
--- a/tests/functional/meson.build
+++ b/tests/functional/meson.build
@@ -37,7 +37,7 @@ test_confdata = {
 # Done as a subdir() so Meson places it under `common` in the build directory as well.
 subdir('common')
 
-config_nix_in = configure_file(
+configure_file(
   input : 'config.nix.in',
   output : 'config.nix',
   configuration : test_confdata,