diff --git a/src/murphy-db/include/murphy-db/mqi-types.h b/src/murphy-db/include/murphy-db/mqi-types.h
index 8ad595ee..d99ae225 100644
--- a/src/murphy-db/include/murphy-db/mqi-types.h
+++ b/src/murphy-db/include/murphy-db/mqi-types.h
@@ -97,6 +97,7 @@ enum mqi_operator_e {
     mqi_less,
     mqi_leq,
     mqi_eq,
+    mqi_neq,
     mqi_geq,
     mqi_gt,
     mqi_not,
diff --git a/src/murphy-db/mdb/cond.c b/src/murphy-db/mdb/cond.c
index 4617e2a9..d466d3a5 100644
--- a/src/murphy-db/mdb/cond.c
+++ b/src/murphy-db/mdb/cond.c
@@ -86,6 +86,7 @@ int mdb_cond_evaluate(mdb_table_t *tbl, mqi_cond_entry_t **cond_ptr,void *data)
         [ mqi_less  ] = 4,
         [ mqi_leq   ] = 4,
         [ mqi_eq    ] = 4,
+        [ mqi_neq   ] = 4,
         [ mqi_geq   ] = 4,
         [ mqi_gt    ] = 4,
         [ mqi_not   ] = 5
@@ -138,6 +139,7 @@ int mdb_cond_evaluate(mdb_table_t *tbl, mqi_cond_entry_t **cond_ptr,void *data)
             case mqi_less:
             case mqi_leq:
             case mqi_eq:
+            case mqi_neq:
             case mqi_geq:
             case mqi_gt:
             case mqi_not:
@@ -245,6 +247,7 @@ static int cond_eval(cond_stack_t *sp,cond_stack_t *lastop,int new_precedence)
         case mqi_less:
         case mqi_leq:
         case mqi_eq:
+        case mqi_neq:
         case mqi_geq:
         case mqi_gt:
             /* stack: (-1)operand1, (0)operator, (1)operand2 => (-1)result */
@@ -327,6 +330,7 @@ static int cond_relop(mqi_operator_t op, cond_stack_t *v1, cond_stack_t *v2)
         case mqi_less:  return cmp <  0;
         case mqi_leq:   return cmp <= 0;
         case mqi_eq:    return cmp == 0;
+        case mqi_neq:   return cmp != 0;
         case mqi_geq:   return cmp >= 0;
         case mqi_gt:    return cmp >  0;
         default:        return 0;
diff --git a/src/murphy-db/mql/mql-parser.y b/src/murphy-db/mql/mql-parser.y
index 8e3ab87e..e5de326a 100644
--- a/src/murphy-db/mql/mql-parser.y
+++ b/src/murphy-db/mql/mql-parser.y
@@ -185,6 +185,7 @@ static FILE        *mqlout;
 %token <string>   TKN_LESS
 %token <string>   TKN_LESS_OR_EQUAL
 %token <string>   TKN_EQUAL
+%token <string>   TKN_NOT_EQUAL
 %token <string>   TKN_GREATER_OR_EQUAL
 %token <string>   TKN_GREATER
 %token <string>   TKN_NOT
@@ -1292,6 +1293,11 @@ relational_operator:
     cond->u.operator_ = mqi_eq;
     cond++;
   }
+| TKN_NOT_EQUAL {
+    cond->type = mqi_operator;
+    cond->u.operator_ = mqi_neq;
+    cond++;
+  }
 | TKN_GREATER_OR_EQUAL {
     cond->type = mqi_operator;
     cond->u.operator_ = mqi_geq;
diff --git a/src/murphy-db/mql/mql-scanner.l b/src/murphy-db/mql/mql-scanner.l
index 3e19650e..825ee4cb 100644
--- a/src/murphy-db/mql/mql-scanner.l
+++ b/src/murphy-db/mql/mql-scanner.l
@@ -149,6 +149,7 @@ LOGICAL_OR        \|
 LESS              <
 LESS_OR_EQUAL     <=
 EQUAL             =
+NOT_EQUAL         \!=
 GREATER_OR_EQUAL  >=
 GREATER           >
 NOT               \!
@@ -222,6 +223,7 @@ SLASH             \/
 {LESS}             { ARGLESS_TOKEN (LESS);             }
 {LESS_OR_EQUAL}    { ARGLESS_TOKEN (LESS_OR_EQUAL);    }
 {EQUAL}            { ARGLESS_TOKEN (EQUAL);            }
+{NOT_EQUAL}        { ARGLESS_TOKEN (NOT_EQUAL);        }
 {GREATER_OR_EQUAL} { ARGLESS_TOKEN (GREATER_OR_EQUAL); }
 {GREATER}          { ARGLESS_TOKEN (GREATER);          }
 {NOT}              { ARGLESS_TOKEN (NOT);              }