diff --git a/cstore/py-cdatapack.h b/cstore/py-cdatapack.h
--- a/cstore/py-cdatapack.h
+++ b/cstore/py-cdatapack.h
@@ -257,13 +257,14 @@
   self->handle = open_datapack(
       idx_path, strlen(idx_path),
       data_path, strlen(data_path));
-  free(data_path);
   free(idx_path);
 
   if (self->handle == NULL) {
     PyErr_NoMemory();
+    free(data_path);
     return -1;
   } else if (self->handle->status == DATAPACK_HANDLE_OK) {
+    free(data_path);
     return 0;
   }
 
@@ -271,9 +272,12 @@
     PyErr_Format(PyExc_RuntimeError, "Unsupported version");
   } else if (self->handle->status != DATAPACK_HANDLE_OK) {
     PyErr_Format(PyExc_ValueError,
-        "Error setting up datapack (status=%d)", self->handle->status);
+        "Error setting up datapack %s (status=%d)",
+        data_path,
+        self->handle->status);
   }
 
+  free(data_path);
   free(self->handle);
   self->handle = NULL;
   return -1;