diff --git a/arangod/Aql/Functions.cpp b/arangod/Aql/Functions.cpp
index bf0d9f1b4b..970410fb01 100644
--- a/arangod/Aql/Functions.cpp
+++ b/arangod/Aql/Functions.cpp
@@ -2395,7 +2395,7 @@ AqlValue Functions::Right(ExpressionContext*, transaction::Methods* trx,
 }
 
 namespace {
-void ltrimInternal(uint32_t& startOffset, uint32_t& endOffset, icu::UnicodeString& unicodeStr,
+void ltrimInternal(int32_t& startOffset, int32_t& endOffset, icu::UnicodeString& unicodeStr,
                    uint32_t numWhitespaces, UChar32* spaceChars) {
   for (; startOffset < endOffset; startOffset = unicodeStr.moveIndex32(startOffset, 1)) {
     bool found = false;
@@ -2412,22 +2412,26 @@ void ltrimInternal(uint32_t& startOffset, uint32_t& endOffset, icu::UnicodeStrin
     }
   }  // for
 }
-void rtrimInternal(uint32_t& startOffset, uint32_t& endOffset, icu::UnicodeString& unicodeStr,
+
+void rtrimInternal(int32_t& startOffset, int32_t& endOffset, icu::UnicodeString& unicodeStr,
                    uint32_t numWhitespaces, UChar32* spaceChars) {
-  for (uint32_t codeUnitPos = unicodeStr.moveIndex32(unicodeStr.length(), -1);
-       startOffset < codeUnitPos;
-       codeUnitPos = unicodeStr.moveIndex32(codeUnitPos, -1)) {
+  if (unicodeStr.length() == 0) {
+    return;
+  }
+  for (int32_t codePos = unicodeStr.moveIndex32(endOffset, -1); 
+       startOffset <= codePos; 
+       codePos = unicodeStr.moveIndex32(codePos, -1)) {
     bool found = false;
 
     for (uint32_t pos = 0; pos < numWhitespaces; pos++) {
-      if (unicodeStr.char32At(codeUnitPos) == spaceChars[pos]) {
+      if (unicodeStr.char32At(codePos) == spaceChars[pos]) {
         found = true;
+        --endOffset;
         break;
       }
     }
 
-    endOffset = unicodeStr.moveIndex32(codeUnitPos, 1);
-    if (!found) {
+    if (!found || codePos == 0) {
       break;
     }
   }  // for
@@ -2475,7 +2479,7 @@ AqlValue Functions::Trim(ExpressionContext* expressionContext, transaction::Meth
     return AqlValue(AqlValueHintNull());
   }
 
-  uint32_t startOffset = 0, endOffset = unicodeStr.length();
+  int32_t startOffset = 0, endOffset = unicodeStr.length();
 
   if (howToTrim <= 1) {
     ltrimInternal(startOffset, endOffset, unicodeStr, numWhitespaces, spaceChars.get());
@@ -2521,7 +2525,7 @@ AqlValue Functions::LTrim(ExpressionContext* expressionContext, transaction::Met
     return AqlValue(AqlValueHintNull());
   }
 
-  uint32_t startOffset = 0, endOffset = unicodeStr.length();
+  int32_t startOffset = 0, endOffset = unicodeStr.length();
 
   ltrimInternal(startOffset, endOffset, unicodeStr, numWhitespaces, spaceChars.get());
 
@@ -2561,7 +2565,7 @@ AqlValue Functions::RTrim(ExpressionContext* expressionContext, transaction::Met
     return AqlValue(AqlValueHintNull());
   }
 
-  uint32_t startOffset = 0, endOffset = unicodeStr.length();
+  int32_t startOffset = 0, endOffset = unicodeStr.length();
 
   rtrimInternal(startOffset, endOffset, unicodeStr, numWhitespaces, spaceChars.get());
 
diff --git a/tests/js/server/aql/aql-functions-string.js b/tests/js/server/aql/aql-functions-string.js
index 056a447a0f..731f23a7c5 100644
--- a/tests/js/server/aql/aql-functions-string.js
+++ b/tests/js/server/aql/aql-functions-string.js
@@ -1480,12 +1480,18 @@ function ahuacatlStringFunctionsTestSuite () {
 // //////////////////////////////////////////////////////////////////////////////
 
   testRtrim: function () {
-    var expected = [ '  foo',
-                      '\t\r\nabc',
-                      '\ta\rb\nc',
-                      '\r\nThis\nis\r\na\ttest'
-                    ];
+    var expected = [ '', 
+                     '', 
+                     '',
+                     '  foo',
+                     '\t\r\nabc',
+                     '\ta\rb\nc',
+                     '\r\nThis\nis\r\na\ttest'
+                   ];
     var actual = getQueryResults(`FOR t IN [
+'',
+' ',
+'   ',
 '  foo  ',
 '\t\r\nabc\n\r\t',
 '\ta\rb\nc ',
@@ -1499,11 +1505,21 @@ function ahuacatlStringFunctionsTestSuite () {
 // //////////////////////////////////////////////////////////////////////////////
 
   testRtrimSpecial1: function () {
-    var expected = [ '  foo',
-                      '\t\r\nabc\n\r\t',
-                      '\ta\rb\nc',
-                      '\r\nThis\nis\r\na\ttest' ];
+    var expected = [ '',
+                     '',
+                     '',
+                     '',
+                     '\t',
+                     '  foo',
+                     '\t\r\nabc\n\r\t',
+                     '\ta\rb\nc',
+                     '\r\nThis\nis\r\na\ttest' ];
     var actual = getQueryResults(`FOR t IN [
+'',
+'\r',
+'\r\n',
+' \r\n',
+'\t\r\n',
 '  foo  ',
 '\t\r\nabc\n\r\t',
 '\ta\rb\nc ',
@@ -1529,6 +1545,20 @@ function ahuacatlStringFunctionsTestSuite () {
     assertEqual(expected, actual);
   },
 
+  testRtrimChars: function () {
+    var expected = [ '10000', '1000', '100', '10', '1', '', '' ];
+    var actual = getQueryResults(`FOR t IN [
+'10000x',
+'1000x',
+'100x',
+'10x',
+'1x',
+'x',
+''
+] RETURN NOOPT((RTRIM(t, 'x') ))`);
+    assertEqual(expected, actual);
+  },
+
 // //////////////////////////////////////////////////////////////////////////////
 // / @brief test find_first function
 // //////////////////////////////////////////////////////////////////////////////