diff --git a/basex-core/src/main/java/org/basex/query/QueryParser.java b/basex-core/src/main/java/org/basex/query/QueryParser.java
index 1dc05acbca..c519a944cf 100644
--- a/basex-core/src/main/java/org/basex/query/QueryParser.java
+++ b/basex-core/src/main/java/org/basex/query/QueryParser.java
@@ -4689,10 +4689,8 @@ private Expr[] ftRange(final boolean i, final Itr min) throws QueryException {
   private Expr ftAdditive(final boolean i) throws QueryException {
     if(!i) return additive();
     skipWs();
-    token.reset();
-    while(digit(current())) token.add(consume());
-    if(token.isEmpty()) throw error(INTEXP);
-    return Itr.get(toLong(token.toArray()));
+    if(!digit(current())) throw error(INTEXP);
+    return numericLiteral(Long.MAX_VALUE, false, false);
   }
 
   /**
diff --git a/basex-core/src/test/java/org/basex/query/ft/FTIndexQueryTest.java b/basex-core/src/test/java/org/basex/query/ft/FTIndexQueryTest.java
index ce96aa5fe7..32f789c049 100644
--- a/basex-core/src/test/java/org/basex/query/ft/FTIndexQueryTest.java
+++ b/basex-core/src/test/java/org/basex/query/ft/FTIndexQueryTest.java
@@ -79,7 +79,16 @@ private static void assertQuery(final String qu) {
         { "//w[text() contains text 'glad' using wildcards" + thes, "l.cky" },
         { "//w[text() contains text 'happy glad' any word" + thes, "lucky\nl.cky" },
         { "//w[text() contains text { 'stil.*' } using wildcards ftor { 'happy' }" + thes,
-          "lucky\na still life\nstill\nstillleben" }
+          "lucky\na still life\nstill\nstillleben" },
+        // GH-2785: underscores in integer literals
+        { "//w[text() contains text 'happy' using thesaurus at '" + db
+          + "' from 0_1 to 1_0 levels]", "lucky" },
+        { "//w[text() contains text 'happy' using thesaurus at '" + db
+            + "' exactly 0_1 levels]", "lucky" },
+        { "//w[text() contains text 'happy' using thesaurus at '" + db
+              + "' at least 0_1 levels]", "lucky" },
+        { "//w[text() contains text 'happy' using thesaurus at '" + db
+                + "' at most 1_0 levels]", "lucky" }
       };
       for(final String[] query : queries) {
         final String qu = query[0] + " ! string()";
diff --git a/basex-core/src/test/java/org/basex/query/ft/FTQueryTest.java b/basex-core/src/test/java/org/basex/query/ft/FTQueryTest.java
index f7896a29e0..8b74c30c68 100644
--- a/basex-core/src/test/java/org/basex/query/ft/FTQueryTest.java
+++ b/basex-core/src/test/java/org/basex/query/ft/FTQueryTest.java
@@ -1,5 +1,6 @@
 package org.basex.query.ft;
 
+import static org.basex.query.QueryError.*;
 import static org.basex.query.func.Function.*;
 
 import org.basex.*;
@@ -95,6 +96,17 @@ public final class FTQueryTest extends SandboxTest {
     query("'a' contains text 'b' using fuzzy 10 errors", true);
   }
 
+  /** Integer separators in full-text ranges. */
+  @Test public void gh2785() {
+    query("'fox' contains text 'cat' using fuzzy 1_0 errors", true);
+    query("'fox' contains text 'cat' using fuzzy 1 errors", false);
+    query("'fox' contains text 'cat' using fuzzy 1__0 errors", true);
+    error("'fox' contains text 'cat' using fuzzy 1_ errors", NUMBER_X);
+    error("'fox' contains text 'cat' using fuzzy _1 errors", QUERYEND_X);
+    error("'fox' contains text 'cat' using fuzzy errors", QUERYEND_X);
+    error("'fox' contains text 'cat' using fuzzy 99999999999999999999 errors", RANGE_X);
+  }
+
   /** Fuzzy search: handling many similar terms. */
   @Test public void gh2014() {
     query(_DB_CREATE.args(NAME, " <a><b>aaaa aabc aaab</b><b>bbbb</b><b>aaad</b></a>",