diff --git a/src/libsysprof-profile/sysprof-battery-charge.c b/src/libsysprof-profile/sysprof-battery-charge.c
index 4ad534f3..5fbb3bd4 100644
--- a/src/libsysprof-profile/sysprof-battery-charge.c
+++ b/src/libsysprof-profile/sysprof-battery-charge.c
@@ -107,14 +107,14 @@ static DexFuture *
 sysprof_battery_charge_record_fiber (gpointer user_data)
 {
   const int invalid_fd = -1;
-  SysprofCaptureCounterValue *values;
-  SysprofCaptureCounter *counters;
+  g_autofree guint *ids = NULL;
+  g_autofree SysprofCaptureCounterValue *values = NULL;
+  g_autofree SysprofCaptureCounter *counters = NULL;
+  g_autofree ReadBuffer *bufs = NULL;
   SysprofCaptureWriter *writer;
   Record *record = user_data;
   g_autoptr(GArray) charge_fds = NULL;
   g_auto(GStrv) names = NULL;
-  ReadBuffer *bufs;
-  guint *ids;
   guint n_names;
   guint n_counters = 1;
 
@@ -127,10 +127,10 @@ sysprof_battery_charge_record_fiber (gpointer user_data)
   n_names = g_strv_length (names);
 
   /* Use some stack space for our counters and values. */
-  ids = g_alloca0 (sizeof *ids * (n_names + 1));
-  counters = g_alloca0 (sizeof *counters * (n_names + 1));
-  values = g_alloca0 (sizeof *values * (n_names + 1));
-  bufs = g_alloca0 (sizeof (ReadBuffer) * (n_names + 1));
+  ids = g_new0 (guint, n_names + 1);
+  counters = g_new0 (SysprofCaptureCounter, n_names + 1);
+  values = g_new0 (SysprofCaptureCounterValue, n_names + 1);
+  bufs = g_new0 (ReadBuffer, n_names + 1);
 
   /* Setup the combined counter which is the total charge of all of
    * the batteries we discover on the system.
diff --git a/src/libsysprof-profile/sysprof-cpu-usage.c b/src/libsysprof-profile/sysprof-cpu-usage.c
index 7fae3677..2b9eaaf1 100644
--- a/src/libsysprof-profile/sysprof-cpu-usage.c
+++ b/src/libsysprof-profile/sysprof-cpu-usage.c
@@ -127,11 +127,11 @@ sysprof_cpu_usage_record_fiber (gpointer user_data)
   g_autoptr(GArray) freq_info = NULL;
   g_autofd int stat_fd = -1;
   g_autofree char *read_buffer = NULL;
-  SysprofCaptureCounterValue *values;
-  SysprofCaptureCounter *counters;
+  g_autofree SysprofCaptureCounterValue *values = NULL;
+  g_autofree SysprofCaptureCounter *counters = NULL;
+  g_autofree guint *ids = NULL;
   SysprofCaptureCounter *counter;
   SysprofCaptureWriter *writer;
-  guint *ids;
   guint n_cpu;
 
   g_assert (record != NULL);
@@ -144,9 +144,9 @@ sysprof_cpu_usage_record_fiber (gpointer user_data)
   g_unix_set_fd_nonblocking (stat_fd, TRUE, NULL);
   read_buffer = g_malloc (PROC_STAT_BUF_SIZE);
 
-  counters = g_alloca (sizeof *counters * ((n_cpu * 2) + 1));
-  ids = g_alloca (sizeof *ids * ((n_cpu * 2) + 1));
-  values = g_alloca (sizeof *values * ((n_cpu * 2) + 1));
+  counters = g_new0 (SysprofCaptureCounter, (n_cpu * 2) + 1);
+  ids = g_new0 (guint, (n_cpu * 2) + 1);
+  values = g_new0 (SysprofCaptureCounterValue, (n_cpu * 2) + 1);
 
   cpu_info = g_array_new (FALSE, TRUE, sizeof (CpuInfo));
   g_array_set_size (cpu_info, n_cpu);