diff --git a/src/runtime/javascript/jspgf.js b/src/runtime/javascript/jspgf.js
index 55c85e10c..801dcd8e9 100644
--- a/src/runtime/javascript/jspgf.js
+++ b/src/runtime/javascript/jspgf.js
@@ -403,16 +403,13 @@ async function mkAPI() {
         asm.gu_pool_free(pool);
     });
 
-    function PGF(pgfPtr,pool) {
+    function PGF(pgfPtr,name,pool) {
         this.pgfPtr = pgfPtr;
+        this.abstractName = name;
         this.pool   = pool;
         this.languages = {};
         registry.register(this,pool);
     }
-    PGF.prototype.abstractName = function() {
-        const namePtr = asm.pgf_abstract_name(this.pgfPtr);
-        return UTF8ToString(namePtr);
-    }
 
     function Concr(pgf,name) {
         this.pgf  = pgf;
@@ -434,7 +431,10 @@ async function mkAPI() {
             throw new Error('Cannot read PGF');
         }
 
-        const pgf = new PGF(pgfPtr,pool);
+        const namePtr = asm.pgf_abstract_name(pgfPtr);
+        const abstractName = UTF8ToString(namePtr);
+
+        const pgf = new PGF(pgfPtr,abstractName,pool);
 
         const itor = asm.gu_malloc(tmp_pool,sizeof_GuMapItor);
         const fn =
diff --git a/src/runtime/javascript/test-web.js b/src/runtime/javascript/test-web.js
index 94b6753bd..e6fd4deec 100644
--- a/src/runtime/javascript/test-web.js
+++ b/src/runtime/javascript/test-web.js
@@ -10,6 +10,6 @@ mkAPI().then((pgf) => {
 
     pgf.readPGF("Foods.pgf").then((gr) => {
         // Print its name
-        console.log(gr.abstractName());
+        console.log(gr.abstractName);
     });
 });