diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8fe48ff..47908c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Jetforce Changelog
 
+### v0.7.0 (unreleased)
+
+#### Spec Changes
+
+- Requests containing URLs without a scheme are no longer accepted.
+
 ### v0.6.0 (2020-07-30)
 
 #### Bugfixes
diff --git a/jetforce/app/base.py b/jetforce/app/base.py
index fbc5571..e7e0fba 100644
--- a/jetforce/app/base.py
+++ b/jetforce/app/base.py
@@ -54,10 +54,9 @@ class Request:
             raise ValueError("Missing hostname component")
 
         if not url_parts.scheme:
-            # If scheme is missing, infer it to be gemini://
-            self.scheme = "gemini"
-        else:
-            self.scheme = url_parts.scheme
+            raise ValueError("Missing scheme component")
+
+        self.scheme = url_parts.scheme
 
         # gemini://username@host/... is forbidden by the specification
         if self.scheme == "gemini" and url_parts.username: