diff --git a/src/libsysprof-capture/sysprof-collector.c b/src/libsysprof-capture/sysprof-collector.c
index 1d7a0d61..22c9d382 100644
--- a/src/libsysprof-capture/sysprof-collector.c
+++ b/src/libsysprof-capture/sysprof-collector.c
@@ -275,7 +275,7 @@ receive_fd_blocking (int peer_fd)
   if ((cmsg->cmsg_len - ((char *)CMSG_DATA (cmsg) - (char *)cmsg)) % 4 != 0)
     return -1;
 
-  fds = (const int *) CMSG_DATA (cmsg);
+  fds = (const int *)(void *)CMSG_DATA (cmsg);
   n_fds = (cmsg->cmsg_len - ((char *)CMSG_DATA (cmsg) - (char *)cmsg)) / sizeof (*fds);
 
   /* only expecting one FD */
diff --git a/src/libsysprof-ui/sysprof-environ-editor.c b/src/libsysprof-ui/sysprof-environ-editor.c
index 58ef2f60..e76d9d0c 100644
--- a/src/libsysprof-ui/sysprof-environ-editor.c
+++ b/src/libsysprof-ui/sysprof-environ-editor.c
@@ -287,12 +287,12 @@ sysprof_environ_editor_new (void)
 
 void
 sysprof_environ_editor_set_environ (SysprofEnvironEditor *self,
-                                    SysprofEnviron       *environ)
+                                    SysprofEnviron       *environ_)
 {
   g_return_if_fail (SYSPROF_IS_ENVIRON_EDITOR (self));
-  g_return_if_fail (SYSPROF_IS_ENVIRON (environ));
+  g_return_if_fail (SYSPROF_IS_ENVIRON (environ_));
 
-  if (self->environ != environ)
+  if (self->environ != environ_)
     {
       if (self->environ != NULL)
         {
@@ -300,9 +300,9 @@ sysprof_environ_editor_set_environ (SysprofEnvironEditor *self,
           g_clear_object (&self->environ);
         }
 
-      if (environ != NULL)
+      if (environ_ != NULL)
         {
-          self->environ = g_object_ref (environ);
+          self->environ = g_object_ref (environ_);
           sysprof_environ_editor_connect (self);
         }
 
diff --git a/src/libsysprof-ui/sysprof-memprof-page.c b/src/libsysprof-ui/sysprof-memprof-page.c
index 80766990..9dd42a88 100644
--- a/src/libsysprof-ui/sysprof-memprof-page.c
+++ b/src/libsysprof-ui/sysprof-memprof-page.c
@@ -205,7 +205,6 @@ update_summary (SysprofMemprofPage    *self,
       g_autofree gchar *subtitle_str = NULL;
       g_autofree gchar *allocstr = NULL;
       g_autofree gchar *tempstr = NULL;
-      g_autofree gchar *leakedstr = NULL;
       g_autofree gchar *allstr = NULL;
       GtkWidget *row;
       GtkWidget *title;
diff --git a/src/libsysprof/sysprof-local-profiler.c b/src/libsysprof/sysprof-local-profiler.c
index 9aecaa7b..62fdea1b 100644
--- a/src/libsysprof/sysprof-local-profiler.c
+++ b/src/libsysprof/sysprof-local-profiler.c
@@ -609,11 +609,11 @@ sysprof_local_profiler_authorize_cb (GObject      *object,
 
       if (priv->spawn_inherit_environ)
         {
-          gchar **environ = g_get_environ ();
+          gchar **environ_ = g_get_environ ();
 
-          for (guint i = 0; environ[i]; i++)
-            g_ptr_array_add (env, environ[i]);
-          g_free (environ);
+          for (guint i = 0; environ_[i]; i++)
+            g_ptr_array_add (env, environ_[i]);
+          g_free (environ_);
         }
 
       if (priv->spawn_env)
diff --git a/src/libsysprof/sysprof-perf-counter.c b/src/libsysprof/sysprof-perf-counter.c
index e896baac..2d0b9f46 100644
--- a/src/libsysprof/sysprof-perf-counter.c
+++ b/src/libsysprof/sysprof-perf-counter.c
@@ -432,7 +432,6 @@ sysprof_perf_counter_open (SysprofPerfCounter     *self,
                            gulong                  flags)
 {
   SysprofHelpers *helpers = sysprof_helpers_get_default ();
-  g_autoptr(GError) error = NULL;
   gint out_fd = -1;
 
   g_return_val_if_fail (self != NULL, -1);
diff --git a/src/libsysprof/sysprof-perf-source.c b/src/libsysprof/sysprof-perf-source.c
index 17e1980e..222520ff 100644
--- a/src/libsysprof/sysprof-perf-source.c
+++ b/src/libsysprof/sysprof-perf-source.c
@@ -206,10 +206,8 @@ sysprof_perf_source_handle_tracepoint (SysprofPerfSource                       *
     {
     case DRM_VBLANK:
       message = g_strdup_printf ("crtc=%d, seq=%u",
-                                 *(gint *)(sample->raw +
-                                           tp_desc->field_offsets[0]),
-                                 *(guint *)(sample->raw +
-                                            tp_desc->field_offsets[1]));
+                                 *(gint *)(gpointer)(sample->raw + tp_desc->field_offsets[0]),
+                                 *(guint *)(gpointer)(sample->raw + tp_desc->field_offsets[1]));
 
       sysprof_capture_writer_add_mark (self->writer,
                                        sample->time,
@@ -224,12 +222,9 @@ sysprof_perf_source_handle_tracepoint (SysprofPerfSource                       *
     case DRM_I915_BEGIN:
     case DRM_I915_END:
       message = g_strdup_printf ("ctx=%u, ring=%u, seqno=%u",
-                                 *(guint *)(sample->raw +
-                                            tp_desc->field_offsets[0]),
-                                 *(guint *)(sample->raw +
-                                            tp_desc->field_offsets[1]),
-                                 *(guint *)(sample->raw +
-                                            tp_desc->field_offsets[2]));
+                                 *(guint *)(gpointer)(sample->raw + tp_desc->field_offsets[0]),
+                                 *(guint *)(gpointer)(sample->raw + tp_desc->field_offsets[1]),
+                                 *(guint *)(gpointer)(sample->raw + tp_desc->field_offsets[2]));
 
       sysprof_capture_writer_add_mark (self->writer,
                                        sample->time,
diff --git a/src/libsysprof/sysprof-proc-source.c b/src/libsysprof/sysprof-proc-source.c
index 181c9cfe..973b5e2a 100644
--- a/src/libsysprof/sysprof-proc-source.c
+++ b/src/libsysprof/sysprof-proc-source.c
@@ -82,7 +82,6 @@ sysprof_proc_source_populate_maps (SysprofProcSource *self,
                                    const gchar       *mountinfostr)
 {
   g_auto(GStrv) maps = NULL;
-  g_auto(GStrv) mountinfo = NULL;
   guint i;
 
   g_assert (SYSPROF_IS_PROC_SOURCE (self));
diff --git a/src/libsysprof/sysprof-spawnable.c b/src/libsysprof/sysprof-spawnable.c
index c206f766..182ccb95 100644
--- a/src/libsysprof/sysprof-spawnable.c
+++ b/src/libsysprof/sysprof-spawnable.c
@@ -166,14 +166,14 @@ sysprof_spawnable_setenv (SysprofSpawnable *self,
 
 void
 sysprof_spawnable_set_environ (SysprofSpawnable    *self,
-                               const gchar * const *environ)
+                               const gchar * const *environ_)
 {
   g_return_if_fail (SYSPROF_IS_SPAWNABLE (self));
 
-  if (environ != (const gchar * const *)self->environ)
+  if (environ_ != (const gchar * const *)self->environ)
     {
       g_strfreev (self->environ);
-      self->environ = g_strdupv ((gchar **)environ);
+      self->environ = g_strdupv ((gchar **)environ_);
     }
 }
 
diff --git a/src/tests/allocs-by-size.c b/src/tests/allocs-by-size.c
index 8231be70..d98e0f6f 100644
--- a/src/tests/allocs-by-size.c
+++ b/src/tests/allocs-by-size.c
@@ -121,7 +121,6 @@ main (gint   argc,
 {
   SysprofCaptureReader *reader;
   const gchar *filename = argv[1];
-  g_autoptr(GError) error = NULL;
 
   if (argc < 2)
     {
diff --git a/src/tests/allocs-within-mark.c b/src/tests/allocs-within-mark.c
index a3ba5b27..e149ab45 100644
--- a/src/tests/allocs-within-mark.c
+++ b/src/tests/allocs-within-mark.c
@@ -186,7 +186,6 @@ main (gint   argc,
 {
   SysprofCaptureReader *reader;
   const gchar *filename;
-  g_autoptr(GError) error = NULL;
   const gchar *category;
   const gchar *name;
 
diff --git a/src/tests/memory-stack-stash.c b/src/tests/memory-stack-stash.c
index 3a277ad7..5078071d 100644
--- a/src/tests/memory-stack-stash.c
+++ b/src/tests/memory-stack-stash.c
@@ -64,7 +64,6 @@ main (gint   argc,
 {
   SysprofCaptureReader *reader;
   const gchar *filename = argv[1];
-  g_autoptr(GError) error = NULL;
 
   if (argc < 2)
     {
diff --git a/src/tests/test-addr-map.c b/src/tests/test-addr-map.c
index 1e7f9b71..6a771586 100644
--- a/src/tests/test-addr-map.c
+++ b/src/tests/test-addr-map.c
@@ -85,7 +85,6 @@ main (gint argc,
       gchar *argv[])
 {
   g_autoptr(SysprofCaptureReader) reader = NULL;
-  g_autoptr(GError) error = NULL;
 
   if (argc != 2)
     {
diff --git a/src/tests/test-mountinfo.c b/src/tests/test-mountinfo.c
index e3902112..e458545a 100644
--- a/src/tests/test-mountinfo.c
+++ b/src/tests/test-mountinfo.c
@@ -26,7 +26,6 @@ main (gint   argc,
 {
   g_autoptr(SysprofMountinfo) info = NULL;
   g_autofree gchar *contents = NULL;
-  g_auto(GStrv) lines = NULL;
   g_autoptr(GError) error = NULL;
   g_autofree gchar *lookup = NULL;
   gsize len;
diff --git a/src/tests/test-resolvers.c b/src/tests/test-resolvers.c
index aadef726..aac7eaf9 100644
--- a/src/tests/test-resolvers.c
+++ b/src/tests/test-resolvers.c
@@ -28,7 +28,6 @@ main (gint  argc,
 {
   g_autoptr(GPtrArray) resolvers = NULL;
   g_autoptr(SysprofCaptureReader) reader = NULL;
-  g_autoptr(GError) error = NULL;
   const SysprofCaptureSample *sample;
   const gchar *filename;
 
@@ -69,7 +68,7 @@ main (gint  argc,
         {
           SysprofAddress addr = sample->addrs[a];
           SysprofAddressContext context;
-          gboolean found;
+          gboolean found = FALSE;
 
            if (sysprof_address_is_context_switch (addr, &context))
              {
diff --git a/src/tools/sysprof-cat.c b/src/tools/sysprof-cat.c
index d023d82d..3bbac8a9 100644
--- a/src/tools/sysprof-cat.c
+++ b/src/tools/sysprof-cat.c
@@ -71,7 +71,6 @@ main (gint   argc,
   for (guint i = 1; i < argc; i++)
     {
       g_autoptr(SysprofCaptureReader) reader = NULL;
-      g_autoptr(GError) error = NULL;
 
       if (!(reader = sysprof_capture_reader_new (argv[i])))
         {