diff --git a/stm32-gen-features/src/lib.rs b/stm32-gen-features/src/lib.rs
index 1ab4865a..cd3a82bc 100644
--- a/stm32-gen-features/src/lib.rs
+++ b/stm32-gen-features/src/lib.rs
@@ -52,7 +52,7 @@ impl FilterSupported for &[(String, Vec<String>)] {
 ///
 /// This function is slow because all the yaml files are parsed.
 pub fn chip_names_and_cores() -> Vec<(String, Vec<String>)> {
-    glob::glob("../stm32-data/data/chips/*.yaml")
+    glob::glob("../stm32-data/data/chips/*.json")
         .unwrap()
         .filter_map(|entry| entry.map_err(|e| eprintln!("{:?}", e)).ok())
         .filter_map(|entry| {