diff --git a/src/document/renderer.c b/src/document/renderer.c
index e860a9249..55c175c4a 100644
--- a/src/document/renderer.c
+++ b/src/document/renderer.c
@@ -392,17 +392,23 @@ render_document(struct view_state *vs, struct document_view *doc_view,
 		       && vs->ecmascript->onload_snippets_cache_id
 		       && document->cache_id != vs->ecmascript->onload_snippets_cache_id))
 			ecmascript_reset_state(vs);
-		assert(vs->ecmascript);
-		vs->ecmascript->onload_snippets_cache_id = document->cache_id;
+		/* If ecmascript_reset_state cannot construct a new
+		 * ECMAScript interpreter, it sets vs->ecmascript =
+		 * NULL and vs->ecmascript_fragile = 1.  */
+		if (vs->ecmascript) {
+			vs->ecmascript->onload_snippets_cache_id = document->cache_id;
 
-		/* Passing of the onload_snippets pointers gives *_snippets()
-		 * some feeling of universality, shall we ever get any other
-		 * snippets (?). */
-		add_snippets(vs->ecmascript,
-		             &document->onload_snippets,
-		             &vs->ecmascript->onload_snippets);
-		process_snippets(vs->ecmascript, &vs->ecmascript->onload_snippets,
-		                 &vs->ecmascript->current_onload_snippet);
+			/* Passing of the onload_snippets pointers
+			 * gives *_snippets() some feeling of
+			 * universality, shall we ever get any other
+			 * snippets (?). */
+			add_snippets(vs->ecmascript,
+				     &document->onload_snippets,
+				     &vs->ecmascript->onload_snippets);
+			process_snippets(vs->ecmascript,
+					 &vs->ecmascript->onload_snippets,
+					 &vs->ecmascript->current_onload_snippet);
+		}
 	}
 #endif
 
diff --git a/src/viewer/text/link.c b/src/viewer/text/link.c
index 543a5a868..7250a4367 100644
--- a/src/viewer/text/link.c
+++ b/src/viewer/text/link.c
@@ -923,7 +923,15 @@ call_onsubmit_and_submit(struct session *ses, struct document_view *doc_view,
 			if (vs->ecmascript_fragile)
 				ecmascript_reset_state(vs);
 			interpreter = vs->ecmascript;
-			assert(interpreter);
+			/* If there is an onsubmit script and we want
+			 * to run it, but the ECMAScript interpreter
+			 * cannot be initialized, then don't submit.  */
+			if (!interpreter) {
+				done_string(&code);
+				/* See the comment below for the
+				 * return value.  */
+				return 1;
+			}
 
 			add_to_string(&code, fc->form->onsubmit);
 			res = ecmascript_eval_boolback(interpreter, &code);