diff --git a/builder/builder-manifest.c b/builder/builder-manifest.c
index 9fb9be49c..859209cce 100644
--- a/builder/builder-manifest.c
+++ b/builder/builder-manifest.c
@@ -956,16 +956,36 @@ builder_manifest_get_id (BuilderManifest *self)
   return self->id;
 }
 
+/* Dashes are only valid in the last part of the app id, so
+   we replace them with underscore so we can suffix the id */
+static char *
+make_valid_id_prefix (const char *orig_id)
+{
+  char *id, *t;
+
+  id = g_strdup (orig_id);
+  t = strchr (id, '-');
+  while (t != NULL)
+    {
+      *t = '_';
+      t = strchr (t + 1, '-');
+    }
+
+  return id;
+}
+
 char *
 builder_manifest_get_locale_id (BuilderManifest *self)
 {
-  return g_strdup_printf ("%s.Locale", self->id);
+  g_autofree char *id = make_valid_id_prefix (self->id);
+  return g_strdup_printf ("%s.Locale", id);
 }
 
 char *
 builder_manifest_get_debug_id (BuilderManifest *self)
 {
-  return g_strdup_printf ("%s.Debug", self->id);
+  g_autofree char *id = make_valid_id_prefix (self->id);
+  return g_strdup_printf ("%s.Debug", id);
 }
 
 const char *
@@ -977,7 +997,15 @@ builder_manifest_get_id_platform (BuilderManifest *self)
 char *
 builder_manifest_get_locale_id_platform (BuilderManifest *self)
 {
-  return g_strdup_printf ("%s.Locale", self->id_platform);
+  char *res = NULL;
+
+  if (self->id_platform != NULL)
+    {
+      g_autofree char *id = make_valid_id_prefix (self->id_platform);
+      res = g_strdup_printf ("%s.Locale", id);
+    }
+
+  return res;
 }
 
 BuilderOptions *