diff --git a/include/json/value.h b/include/json/value.h
index fe2f9eb..19e2966 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -317,8 +317,10 @@ namespace Json {
 //      EnumValues enumValues() const;
 //# endif
 
+      /// Comments must be //... or /* ... */
       void setComment( const char *comment,
                        CommentPlacement placement );
+      /// Comments must be //... or /* ... */
       void setComment( const std::string &comment,
                        CommentPlacement placement );
       bool hasComment( CommentPlacement placement ) const;
diff --git a/src/lib_json/json_value.cpp b/src/lib_json/json_value.cpp
index b3e90b6..0fb735f 100644
--- a/src/lib_json/json_value.cpp
+++ b/src/lib_json/json_value.cpp
@@ -1,3 +1,4 @@
+#include <iostream>
 #include <json/value.h>
 #include <json/writer.h>
 #include <utility>
@@ -149,6 +150,9 @@ Value::CommentInfo::setComment( const char *text )
 {
    if ( comment_ )
       valueAllocator()->releaseStringValue( comment_ );
+   JSON_ASSERT( text );
+   JSON_ASSERT_MESSAGE( text[0]==NULL || text[0]=='/', "Comments must start with /");
+   // It seems that /**/ style comments are acceptable as well.
    comment_ = valueAllocator()->duplicateStringValue( text );
 }