diff --git a/client.c b/client.c
index 5c767e11..d9566e15 100644
--- a/client.c
+++ b/client.c
@@ -43,11 +43,12 @@ static const char *
 version_and_features(void)
 {
     static char buf[256];
-    snprintf(buf, sizeof(buf), "version: %s %cpgo %cime %cgraphemes",
+    snprintf(buf, sizeof(buf), "version: %s %cpgo %cime %cgraphemes %cassertions",
              FOOT_VERSION,
              feature_pgo() ? '+' : '-',
              feature_ime() ? '+' : '-',
-             feature_graphemes() ? '+' : '-');
+             feature_graphemes() ? '+' : '-',
+             feature_assertions() ?  '+' : '-');
     return buf;
 }
 
diff --git a/foot-features.h b/foot-features.h
index cdc8056f..ad447767 100644
--- a/foot-features.h
+++ b/foot-features.h
@@ -2,6 +2,15 @@
 
 #include <stdbool.h>
 
+static inline bool feature_assertions(void)
+{
+#if defined(NDEBUG)
+    return false;
+#else
+    return true;
+#endif
+}
+
 static inline bool feature_ime(void)
 {
 #if defined(FOOT_IME_ENABLED) && FOOT_IME_ENABLED
diff --git a/main.c b/main.c
index fd27aebd..07f58080 100644
--- a/main.c
+++ b/main.c
@@ -45,11 +45,12 @@ static const char *
 version_and_features(void)
 {
     static char buf[256];
-    snprintf(buf, sizeof(buf), "version: %s %cpgo %cime %cgraphemes",
+    snprintf(buf, sizeof(buf), "version: %s %cpgo %cime %cgraphemes %cassertions",
              FOOT_VERSION,
              feature_pgo() ? '+' : '-',
              feature_ime() ? '+' : '-',
-             feature_graphemes() ? '+' : '-');
+             feature_graphemes() ? '+' : '-',
+             feature_assertions() ? '+' : '-');
     return buf;
 }