diff --git a/lib/pep440.nix b/lib/pep440.nix
index 0b5f834..3057ce4 100644
--- a/lib/pep440.nix
+++ b/lib/pep440.nix
@@ -151,7 +151,7 @@ fix (self: {
   */
   parseVersionCond = cond: (
     let
-      m = match " *([=><!~^]+) *(.+)" cond;
+      m = match " *([=><!~^]*) *(.+)" cond;
       mAt = elemAt m;
     in
     {
@@ -256,6 +256,7 @@ fix (self: {
     "<" = a: b: self.compareVersions a b < 0;
     ">" = a: b: self.compareVersions a b > 0;
     "===" = throw "Arbitrary equality clause not supported";
+    "" = _a: _b: true;
   };
 
 })
diff --git a/lib/test_pep440.nix b/lib/test_pep440.nix
index 2128928..9fc54ef 100644
--- a/lib/test_pep440.nix
+++ b/lib/test_pep440.nix
@@ -240,6 +240,21 @@ in
         };
       };
     };
+
+    testNoOp = {
+      expr = parseVersionCond "*";
+      expected = {
+        op = "";
+        version = {
+          dev = null;
+          epoch = 0;
+          local = null;
+          post = null;
+          pre = null;
+          release = [ "*" ];
+        };
+      };
+    };
   };
 
   comparators = {