diff --git a/rfc3986.rl b/rfc3986.rl
index b0ae57d3..8171bba5 100644
--- a/rfc3986.rl
+++ b/rfc3986.rl
@@ -32,7 +32,9 @@
     pct_encoded = '%' xdigit xdigit;
     gen_delim = ":" | "/" | "?" | "#" | "[" | "]" | "@";
     sub_delim = "!" | "$" | "&" | "'" | "(" | ")" | "*" | "+" | "," | ";" | "=";
-    pchar = unreserved | pct_encoded | sub_delim | ':' | '@';
+    # double quote is allowed here because it's quite common in real life and
+    # we don't have a great way to work around it here.
+    pchar = unreserved | pct_encoded | sub_delim | ':' | '@' | '"';
 
     ## Atoms
     reg_name = (unreserved | pct_encoded | sub_delim)*;
diff --git a/test/uri.cpp b/test/uri.cpp
index 945b7623..72199a41 100644
--- a/test/uri.cpp
+++ b/test/uri.cpp
@@ -339,12 +339,45 @@ test_resolve (cruft::TAP::logger &tap)
 }
 
 
+///////////////////////////////////////////////////////////////////////////////
+static
+void
+test_validity (cruft::TAP::logger &tap)
+{
+    static char const *GOOD[] = {
+        "http://[2001:db8::7]/",
+        "http://[2001:db8::7]:80/",
+        "http://user@example.com:10/",
+        "http://user@example.com",
+        "http://example.com:443/",
+        "https://example.com:80/",
+        "http://example.com/foo?bar=qux#xyz",
+        "http://example.com/?bar=qux#xyz",
+        "http://example.com/#xyz",
+        "http://example.com/???",
+        "http://example.com/?#?",
+        "http://example.com/%22",
+    };
+
+    for (auto const &good: GOOD)
+        tap.expect_nothrow ([&] (void) { (void) cruft::uri (good); }, "parse: {}", good);
+
+    static char const *BAD[] = {
+        // "http://example.com/?foo=\"bar\"",
+    };
+
+    for (auto const &bad: BAD)
+        tap.expect_throw<std::exception> ([&] (void) { (void) cruft::uri (bad); }, "parse: {}", bad);
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 int
 main (void)
 {
     cruft::TAP::logger tap;
 
+    test_validity (tap);
     test_parse (tap);
     test_normalise (tap);
     test_rfc_resolve (tap);
diff --git a/uri.cpp b/uri.cpp
index 43fc4a50..c5017d00 100644
--- a/uri.cpp
+++ b/uri.cpp
@@ -9,7 +9,6 @@
 using cruft::uri;
 
 
-
 ///////////////////////////////////////////////////////////////////////////////
 #include <cruft/util/debug/assert.hpp>
 #include <cruft/util/debug/warn.hpp>