diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 30f0031905f1..051871020af7 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -571,11 +571,8 @@ config_data! {
         /// avoid checking unnecessary things.
         cargo_buildScripts_useRustcWrapper: bool = true,
         /// List of cfg options to enable with the given values.
-        cargo_cfgs: FxHashMap<String, Option<String>> = {
-            let mut m = FxHashMap::default();
-            m.insert("debug_assertions".to_owned(), None);
-            m.insert("miri".to_owned(), None);
-            m
+        cargo_cfgs: Vec<String> = {
+            vec!["debug_assertion".into(), "miri".into()]
         },
         /// Extra arguments that are passed to every cargo invocation.
         cargo_extraArgs: Vec<String> = vec![],
@@ -1944,6 +1941,13 @@ impl Config {
                 global: CfgDiff::new(
                     self.cargo_cfgs(source_root)
                         .iter()
+                        // parse any cfg setting formatted as key=value or just key (without value)
+                        .filter_map(|s| {
+                            let mut sp = s.splitn(2, "=");
+                            let key = sp.next();
+                            let val = sp.next();
+                            key.map(|key| (key, val))
+                        })
                         .map(|(key, val)| match val {
                             Some(val) => CfgAtom::KeyValue {
                                 key: Symbol::intern(key),
diff --git a/docs/user/generated_config.adoc b/docs/user/generated_config.adoc
index 5b86766aa8ea..c6f5852f87ff 100644
--- a/docs/user/generated_config.adoc
+++ b/docs/user/generated_config.adoc
@@ -94,10 +94,10 @@ avoid checking unnecessary things.
 --
 Default:
 ----
-{
-  "miri": null,
-  "debug_assertions": null
-}
+[
+  "debug_assertion",
+  "miri"
+]
 ----
 List of cfg options to enable with the given values.
 
diff --git a/editors/code/package.json b/editors/code/package.json
index 80246bf3feac..6cb74a94a00c 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -791,11 +791,14 @@
                 "properties": {
                     "rust-analyzer.cargo.cfgs": {
                         "markdownDescription": "List of cfg options to enable with the given values.",
-                        "default": {
-                            "miri": null,
-                            "debug_assertions": null
-                        },
-                        "type": "object"
+                        "default": [
+                            "debug_assertion",
+                            "miri"
+                        ],
+                        "type": "array",
+                        "items": {
+                            "type": "string"
+                        }
                     }
                 }
             },