diff --git a/Documentation/Getting-Started/Configuration-Guide.md b/Documentation/Getting-Started/Configuration-Guide.md
index 3a770fa4e..ebd6943fc 100644
--- a/Documentation/Getting-Started/Configuration-Guide.md
+++ b/Documentation/Getting-Started/Configuration-Guide.md
@@ -82,6 +82,14 @@ The values of the parameter that are not on the first line need to have at least
 one whitespace character before them in order for them to be recognized as a
 part of the multi-line parameter.
 
+Comments are defined by prefixing a row with a hash (`#`). Trailing comments are
+not supported.
+
+```
+# This is a comment before a parameter
+some_parameter=123
+```
+
 ### Special Parameter Types
 
 #### Sizes
diff --git a/server/core/queryclassifier.cc b/server/core/queryclassifier.cc
index 3bb0bd84b..ec7b5a49a 100644
--- a/server/core/queryclassifier.cc
+++ b/server/core/queryclassifier.cc
@@ -100,7 +100,7 @@ bool are_multi_statements_allowed(MXS_SESSION* pSession)
 
 uint32_t get_prepare_type(GWBUF* buffer)
 {
-    uint32_t type;
+    uint32_t type = QUERY_TYPE_UNKNOWN;
 
     if (mxs_mysql_get_command(buffer) == MXS_COM_STMT_PREPARE)
     {
@@ -127,9 +127,11 @@ uint32_t get_prepare_type(GWBUF* buffer)
     else
     {
         GWBUF* stmt = qc_get_preparable_stmt(buffer);
-        ss_dassert(stmt);
 
-        type = qc_get_type_mask(stmt);
+        if (stmt)
+        {
+            type = qc_get_type_mask(stmt);
+        }
     }
 
     ss_dassert((type & (QUERY_TYPE_PREPARE_STMT | QUERY_TYPE_PREPARE_NAMED_STMT)) == 0);