diff --git a/.papr.yml b/.papr.yml
index 6946b936..1addf061 100644
--- a/.papr.yml
+++ b/.papr.yml
@@ -12,7 +12,9 @@ packages:
   - git
 
 env:
-    CFLAGS: '-fsanitize=undefined -fsanitize-undefined-trap-on-error -fsanitize=address -O2 -Wp,-D_FORTIFY_SOURCE=2'
+    # Enable all the sanitizers for this primary build.
+    # We only use -Werror=maybe-uninitialized here with a "fixed" toolchain
+    CFLAGS: '-fsanitize=undefined -fsanitize-undefined-trap-on-error -fsanitize=address -O2 -Wp,-D_FORTIFY_SOURCE=2 -Werror=maybe-uninitialized'
     ASAN_OPTIONS: 'detect_leaks=0'  # Right now we're not fully clean, but this gets us use-after-free etc
     # TODO when we're doing leak checks: G_SLICE: "always-malloc"