diff --git a/extra/mkkeywordhash.c b/extra/mkkeywordhash.c
index be7bd5545260..94a768323ecc 100644
--- a/extra/mkkeywordhash.c
+++ b/extra/mkkeywordhash.c
@@ -91,6 +91,7 @@ struct Keyword {
 #  define CTE        0x00040000
 #endif
 #  define RESERVED   0x00000001
+#  define FUNCTION   0x00080000
 /*
 ** These are the keywords
 */
@@ -202,6 +203,7 @@ static Keyword aKeywordTable[] = {
   { "TO",                     "TK_TO",          ALWAYS,           true  },
   { "TRANSACTION",            "TK_TRANSACTION", ALWAYS,           true  },
   { "TRIGGER",                "TK_TRIGGER",     TRIGGER,          true  },
+  { "TRIM",                   "TK_TRIM",        FUNCTION,         true  },
   { "UNION",                  "TK_UNION",       COMPOUND,         true  },
   { "UNIQUE",                 "TK_UNIQUE",      ALWAYS,           true  },
   { "UPDATE",                 "TK_UPDATE",      ALWAYS,           true  },
@@ -278,6 +280,9 @@ static Keyword aKeywordTable[] = {
   { "WHILE",                  "TK_STANDARD",    RESERVED,         true  },
   { "TEXT",                   "TK_TEXT",        RESERVED,         true  },
   { "TRUNCATE",               "TK_TRUNCATE",    ALWAYS,           true  },
+  { "LEADING",                "TK_LEADING",     ALWAYS,           true  },
+  { "TRAILING",               "TK_TRAILING",    ALWAYS,           true  },
+  { "BOTH",                   "TK_BOTH",        ALWAYS,           true  },
 };
 
 /* Number of keywords */
diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index a750e52a1b5f..07d3cd25d4dd 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -1207,8 +1207,7 @@ replaceFunc(sql_context * context, int argc, sql_value ** argv)
 }
 
 /*
- * Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
- * The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
+ * Implementation of the TRIM() function.
  */
 static void
 trimFunc(sql_context * context, int argc, sql_value ** argv)
@@ -1216,32 +1215,49 @@ trimFunc(sql_context * context, int argc, sql_value ** argv)
 	const unsigned char *zIn;	/* Input string */
 	const unsigned char *zCharSet;	/* Set of characters to trim */
 	int nIn;		/* Number of bytes in input */
-	int flags;		/* 1: trimleft  2: trimright  3: trim */
 	int i;			/* Loop counter */
 	unsigned char *aLen = 0;	/* Length of each character in zCharSet */
 	unsigned char **azChar = 0;	/* Individual characters in zCharSet */
 	int nChar;		/* Number of characters in zCharSet */
+	/* The index of trim source in the argv array.*/
+	int source_index = argc - 1;
+	/* True if character set has been passed, false if has't been. */
+	bool set = true;
+	/* 1: if it's left side.
+	 * 2: if it's right side.
+	 * 3: if it's both sides. */
+	int trim_side = 3;
+
+	/* If we have 2 agrs, the first can be trimiing side or character set.
+	 * If we have 3 agrs, the first can be triiming side only, i.e. number. */
+	if (argc == 2 && sql_value_type(argv[0]) == SQL_INTEGER) {
+		trim_side = sql_value_int(argv[0]);
+		set = false;
+	} else if (argc == 3) {
+		trim_side = sql_value_int(argv[0]);
+	}
 
-	if (sql_value_type(argv[0]) == SQL_NULL) {
+	if (sql_value_type(argv[source_index]) == SQL_NULL) {
 		return;
 	}
-	zIn = sql_value_text(argv[0]);
+
+	zIn = sql_value_text(argv[source_index]);
 	if (zIn == 0)
 		return;
-	nIn = sql_value_bytes(argv[0]);
-	assert(zIn == sql_value_text(argv[0]));
-	if (argc == 1) {
+	nIn = sql_value_bytes(argv[source_index]);
+	assert(zIn == sql_value_text(argv[source_index]));
+	if (source_index == 0 || set == false ) {
 		static const unsigned char lenOne[] = { 1 };
 		static unsigned char *const azOne[] = { (u8 *) " " };
 		nChar = 1;
 		aLen = (u8 *) lenOne;
 		azChar = (unsigned char **)azOne;
 		zCharSet = 0;
-	} else if ((zCharSet = sql_value_text(argv[1])) == 0) {
+	} else if ((zCharSet = sql_value_text(argv[source_index - 1])) == 0) {
 		return;
 	} else {
 		const unsigned char *z = zCharSet;
-		int trim_set_sz = sql_value_bytes(argv[1]);
+		int trim_set_sz = sql_value_bytes(argv[source_index - 1]);
 		/*
 		* Count the number of UTF-8 characters passing
 		* through the entire char set, but not up
@@ -1272,8 +1288,7 @@ trimFunc(sql_context * context, int argc, sql_value ** argv)
 		}
 	}
 	if (nChar > 0) {
-		flags = SQL_PTR_TO_INT(sql_user_data(context));
-		if (flags & 1) {
+		if (trim_side & 1) {
 			while (nIn > 0) {
 				int len = 0;
 				for (i = 0; i < nChar; i++) {
@@ -1288,7 +1303,7 @@ trimFunc(sql_context * context, int argc, sql_value ** argv)
 				nIn -= len;
 			}
 		}
-		if (flags & 2) {
+		if (trim_side & 2) {
 			while (nIn > 0) {
 				int len = 0;
 				for (i = 0; i < nChar; i++) {
@@ -1738,12 +1753,9 @@ sqlRegisterBuiltinFunctions(void)
 			  FIELD_TYPE_INTEGER),
 		FUNCTION2(likely, 1, 0, 0, noopFunc, SQL_FUNC_UNLIKELY,
 			  FIELD_TYPE_INTEGER),
-		FUNCTION_COLL(ltrim, 1, 1, 0, trimFunc),
-		FUNCTION_COLL(ltrim, 2, 1, 0, trimFunc),
-		FUNCTION_COLL(rtrim, 1, 2, 0, trimFunc),
-		FUNCTION_COLL(rtrim, 2, 2, 0, trimFunc),
 		FUNCTION_COLL(trim, 1, 3, 0, trimFunc),
 		FUNCTION_COLL(trim, 2, 3, 0, trimFunc),
+		FUNCTION_COLL(trim, 3, 3, 0, trimFunc),
 		FUNCTION(min, -1, 0, 1, minmaxFunc, FIELD_TYPE_SCALAR),
 		FUNCTION(min, 0, 0, 1, 0, FIELD_TYPE_SCALAR),
 		AGGREGATE2(min, 1, 0, 1, minmaxStep, minMaxFinalize,
diff --git a/src/box/sql/global.c b/src/box/sql/global.c
index 95ad71c38e8e..fccf74100d8c 100644
--- a/src/box/sql/global.c
+++ b/src/box/sql/global.c
@@ -223,11 +223,13 @@ SQL_WSD struct sqlConfig sqlConfig = {
 FuncDefHash sqlBuiltinFunctions;
 
 /*
- * Constant tokens for values 0 and 1.
+ * Constant tokens for necessary integer values.
  */
 const Token sqlIntTokens[] = {
 	{"0", 1, false},
-	{"1", 1, false}
+	{"1", 1, false},
+	{"2", 1, false},
+	{"3", 1, false}
 };
 
 /*
diff --git a/src/box/sql/parse.y b/src/box/sql/parse.y
index d2614d9b0add..53e5fd932456 100644
--- a/src/box/sql/parse.y
+++ b/src/box/sql/parse.y
@@ -937,6 +937,54 @@ expr(A) ::= CAST(X) LP expr(E) AS typedef(T) RP(Y). {
   sqlExprAttachSubtrees(pParse->db, A.pExpr, E.pExpr, 0);
 }
 %endif  SQL_OMIT_CAST
+
+expr(A) ::= TRIM(X) LP trim_operands(Y) RP(E). {
+  A.pExpr = sqlExprFunction(pParse, Y, &X);
+  spanSet(&A, &X, &E);
+}
+
+%type trim_operands {ExprList*}
+%destructor trim_operands {sql_expr_list_delete(pParse->db, $$);}
+
+trim_operands(A) ::= from_clause(F) trim_source(Y). {
+  A = sql_expr_list_append(pParse->db, F, Y);
+}
+trim_operands(A) ::= trim_source(Y). {
+  A = sql_expr_list_append(pParse->db, NULL, Y);
+}
+
+%type trim_source {Expr*}
+%destructor trim_source {sql_expr_delete(pParse->db, $$, false);}
+
+trim_source(A) ::= expr(X). {A = X.pExpr;}
+
+%type from_clause {ExprList*}
+%destructor from_clause { sql_expr_list_delete(pParse->db, $$); }
+
+from_clause(A) ::= trim_specification(N) trim_set(Y) FROM. {
+  struct Expr* p = sqlExprAlloc(pParse->db, TK_INTEGER, &sqlIntTokens[N], 1);
+  A = sql_expr_list_append(pParse->db, NULL, p);
+  if (Y != 0) {
+    A = sql_expr_list_append(pParse->db, A, Y);
+  }
+}
+
+from_clause(A) ::= trim_set(Y) FROM. {
+  A = sql_expr_list_append(pParse->db, NULL, Y);
+}
+
+%type trim_set {Expr*}
+%destructor trim_set {sql_expr_delete(pParse->db, $$, false);}
+
+trim_set(A) ::= . {A = 0;}
+trim_set(A) ::= expr(X). {A = X.pExpr;}
+
+%type trim_specification {int}
+
+trim_specification(A) ::= LEADING.  {A = 1;}
+trim_specification(A) ::= TRAILING. {A = 2;}
+trim_specification(A) ::= BOTH.     {A = 3;}
+
 expr(A) ::= id(X) LP distinct(D) exprlist(Y) RP(E). {
   if( Y && Y->nExpr>pParse->db->aLimit[SQL_LIMIT_FUNCTION_ARG] ){
     const char *err =
diff --git a/test/sql-tap/badutf1.test.lua b/test/sql-tap/badutf1.test.lua
index d104efaa980d..d32bafae0e4b 100755
--- a/test/sql-tap/badutf1.test.lua
+++ b/test/sql-tap/badutf1.test.lua
@@ -302,7 +302,7 @@ test:do_test(
 test:do_test(
     "badutf-4.1",
     function()
-        return test:execsql2("SELECT hex(trim('\x80\x80\x80\xf0\x80\x80\x80\xff','\x80\xff')) AS x")
+        return test:execsql2("SELECT hex(trim('\x80\xff' FROM '\x80\x80\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.1>
         "X", "F0"
@@ -312,7 +312,7 @@ test:do_test(
 test:do_test(
     "badutf-4.2",
     function()
-        return test:execsql2("SELECT hex(ltrim('\x80\x80\x80\xf0\x80\x80\x80\xff','\x80\xff')) AS x")
+        return test:execsql2("SELECT hex(trim(LEADING '\x80\xff' FROM '\x80\x80\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.2>
         "X", "F0808080FF"
@@ -322,7 +322,7 @@ test:do_test(
 test:do_test(
     "badutf-4.3",
     function()
-        return test:execsql2("SELECT hex(rtrim('\x80\x80\x80\xf0\x80\x80\x80\xff','\x80\xff')) AS x")
+        return test:execsql2("SELECT hex(trim(TRAILING '\x80\xff' FROM '\x80\x80\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.3>
         "X", "808080F0"
@@ -332,7 +332,7 @@ test:do_test(
 test:do_test(
     "badutf-4.4",
     function()
-        return test:execsql2("SELECT hex(trim('\x80\x80\x80\xf0\x80\x80\x80\xff','\xff\x80')) AS x")
+        return test:execsql2("SELECT hex(trim('\xff\x80' FROM '\x80\x80\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.4>
         "X", "808080F0808080FF"
@@ -342,7 +342,7 @@ test:do_test(
 test:do_test(
     "badutf-4.5",
     function()
-        return test:execsql2("SELECT hex(trim('\xff\x80\x80\xf0\x80\x80\x80\xff','\xff\x80')) AS x")
+        return test:execsql2("SELECT hex(trim('\xff\x80' FROM '\xff\x80\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.5>
         "X", "80F0808080FF"
@@ -352,7 +352,7 @@ test:do_test(
 test:do_test(
     "badutf-4.6",
     function()
-        return test:execsql2("SELECT hex(trim('\xff\x80\xf0\x80\x80\x80\xff','\xff\x80')) AS x")
+        return test:execsql2("SELECT hex(trim('\xff\x80' FROM '\xff\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.6>
         "X", "F0808080FF"
@@ -362,7 +362,7 @@ test:do_test(
 test:do_test(
     "badutf-4.7",
     function()
-        return test:execsql2("SELECT hex(trim('\xff\x80\xf0\x80\x80\x80\xff','\xff\x80\x80')) AS x")
+        return test:execsql2("SELECT hex(trim('\xff\x80\x80' FROM '\xff\x80\xf0\x80\x80\x80\xff')) AS x")
     end, {
         -- <badutf-4.7>
         "X", "FF80F0808080FF"
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index 889fc5867e5d..d9c96c5bd0e6 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -1,6 +1,6 @@
 #!/usr/bin/env tarantool
 test = require("sqltester")
-test:plan(14586)
+test:plan(14589)
 
 --!./tcltestrunner.lua
 -- 2001 September 15
@@ -1912,37 +1912,37 @@ test:do_test(
 test:do_catchsql_test(
     "func-22.1",
     [[
-        SELECT trim(1,2,3)
+        SELECT TRIM(1,2,3)
     ]], {
         -- <func-22.1>
-        1, "wrong number of arguments to function TRIM()"
+        1, "Syntax error near ','"
         -- </func-22.1>
     })
 
 test:do_catchsql_test(
     "func-22.2",
     [[
-        SELECT ltrim(1,2,3)
+        SELECT LTRIM(1,2,3)
     ]], {
         -- <func-22.2>
-        1, "wrong number of arguments to function LTRIM()"
+        1, "Function 'LTRIM' does not exist"
         -- </func-22.2>
     })
 
 test:do_catchsql_test(
     "func-22.3",
     [[
-        SELECT rtrim(1,2,3)
+        SELECT RTRIM(1,2,3)
     ]], {
         -- <func-22.3>
-        1, "wrong number of arguments to function RTRIM()"
+        1, "Function 'RTRIM' does not exist"
         -- </func-22.3>
     })
 
 test:do_execsql_test(
     "func-22.4",
     [[
-        SELECT trim('  hi  ');
+        SELECT TRIM('  hi  ');
     ]], {
         -- <func-22.4>
         "hi"
@@ -1952,7 +1952,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.5",
     [[
-        SELECT ltrim('  hi  ');
+        SELECT TRIM(LEADING FROM '  hi  ');
     ]], {
         -- <func-22.5>
         "hi  "
@@ -1962,7 +1962,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.6",
     [[
-        SELECT rtrim('  hi  ');
+        SELECT TRIM(TRAILING FROM '  hi  ');
     ]], {
         -- <func-22.6>
         "  hi"
@@ -1972,7 +1972,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.7",
     [[
-        SELECT trim('  hi  ','xyz');
+        SELECT TRIM('xyz' FROM '  hi  ');
     ]], {
         -- <func-22.7>
         "  hi  "
@@ -1982,7 +1982,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.8",
     [[
-        SELECT ltrim('  hi  ','xyz');
+        SELECT TRIM(LEADING 'xyz' FROM '  hi  ');
     ]], {
         -- <func-22.8>
         "  hi  "
@@ -1992,7 +1992,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.9",
     [[
-        SELECT rtrim('  hi  ','xyz');
+        SELECT TRIM(TRAILING 'xyz' FROM '  hi  ');
     ]], {
         -- <func-22.9>
         "  hi  "
@@ -2002,7 +2002,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.10",
     [[
-        SELECT trim('xyxzy  hi  zzzy','xyz');
+        SELECT TRIM('xyz' FROM 'xyxzy  hi  zzzy');
     ]], {
         -- <func-22.10>
         "  hi  "
@@ -2012,7 +2012,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.11",
     [[
-        SELECT ltrim('xyxzy  hi  zzzy','xyz');
+        SELECT TRIM(LEADING 'xyz' FROM 'xyxzy  hi  zzzy');
     ]], {
         -- <func-22.11>
         "  hi  zzzy"
@@ -2022,7 +2022,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.12",
     [[
-        SELECT rtrim('xyxzy  hi  zzzy','xyz');
+        SELECT TRIM(TRAILING 'xyz' FROM 'xyxzy  hi  zzzy');
     ]], {
         -- <func-22.12>
         "xyxzy  hi  "
@@ -2032,7 +2032,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.13",
     [[
-        SELECT trim('  hi  ','');
+        SELECT TRIM('' FROM '  hi  ');
     ]], {
         -- <func-22.13>
         "  hi  "
@@ -2043,7 +2043,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.14",
     [[
-        SELECT hex(trim(x'c280e1bfbff48fbfbf6869',x'6162e1bfbfc280'))
+        SELECT hex(TRIM(x'6162e1bfbfc280' FROM x'c280e1bfbff48fbfbf6869'))
     ]], {
         -- <func-22.14>
         "F48FBFBF6869"
@@ -2052,8 +2052,8 @@ test:do_execsql_test(
 
 test:do_execsql_test(
     "func-22.15",
-    [[SELECT hex(trim(x'6869c280e1bfbff48fbfbf61',
-                         x'6162e1bfbfc280f48fbfbf'))]], {
+    [[SELECT hex(TRIM(x'6162e1bfbfc280f48fbfbf'
+                      FROM x'6869c280e1bfbff48fbfbf61'))]], {
         -- <func-22.15>
         "6869"
         -- </func-22.15>
@@ -2062,7 +2062,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.16",
     [[
-        SELECT hex(trim(x'ceb1ceb2ceb3',x'ceb1'));
+        SELECT hex(TRIM(x'ceb1' FROM x'ceb1ceb2ceb3'));
     ]], {
         -- <func-22.16>
         "CEB2CEB3"
@@ -2073,7 +2073,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.20",
     [[
-        SELECT typeof(trim(NULL));
+        SELECT typeof(TRIM(NULL));
     ]], {
         -- <func-22.20>
         "null"
@@ -2083,7 +2083,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.21",
     [[
-        SELECT typeof(trim(NULL,'xyz'));
+        SELECT typeof(TRIM('xyz' FROM NULL));
     ]], {
         -- <func-22.21>
         "null"
@@ -2093,7 +2093,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.22",
     [[
-        SELECT typeof(trim('hello',NULL));
+        SELECT typeof(TRIM(NULL FROM 'hello'));
     ]], {
         -- <func-22.22>
         "null"
@@ -2105,7 +2105,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.23",
     [[
-        SELECT TRIM(X'004100', X'00');
+        SELECT TRIM(X'00' FROM X'004100');
     ]], {
         -- <func-22.23>
         "A"
@@ -2115,7 +2115,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.24",
     [[
-        SELECT TRIM(X'004100', X'0000');
+        SELECT TRIM(X'0000' FROM X'004100');
     ]], {
         -- <func-22.24>
         "A"
@@ -2125,7 +2125,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.25",
     [[
-        SELECT TRIM(X'004100', X'0042');
+        SELECT TRIM(X'0042' FROM X'004100');
     ]], {
         -- <func-22.25>
         "A"
@@ -2135,7 +2135,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.26",
     [[
-        SELECT TRIM(X'00004100420000', X'00');
+        SELECT TRIM(X'00' FROM X'00004100420000');
     ]], {
         -- <func-22.26>
         "A\0B"
@@ -2145,7 +2145,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.27",
     [[
-        SELECT LTRIM(X'004100', X'00');
+        SELECT TRIM(LEADING X'00' FROM X'004100');
     ]], {
         -- <func-22.27>
         "A\0"
@@ -2155,7 +2155,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.28",
     [[
-        SELECT LTRIM(X'004100', X'0000');
+        SELECT TRIM(LEADING X'0000' FROM X'004100');
     ]], {
         -- <func-22.28>
         "A\0"
@@ -2165,7 +2165,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.29",
     [[
-        SELECT LTRIM(X'004100', X'0042');
+        SELECT TRIM(LEADING X'0042' FROM X'004100');
     ]], {
         -- <func-22.29>
         "A\0"
@@ -2175,7 +2175,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.30",
     [[
-        SELECT LTRIM(X'00004100420000', X'00');
+        SELECT TRIM(LEADING X'00' FROM X'00004100420000');
     ]], {
         -- <func-22.30>
         "A\0B\0\0"
@@ -2185,7 +2185,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.31",
     [[
-        SELECT RTRIM(X'004100', X'00');
+        SELECT TRIM(TRAILING X'00' FROM X'004100');
     ]], {
         -- <func-22.31>
         "\0A"
@@ -2195,7 +2195,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.32",
     [[
-        SELECT RTRIM(X'004100', X'0000');
+        SELECT TRIM(TRAILING X'0000' FROM X'004100');
     ]], {
         -- <func-22.32>
         "\0A"
@@ -2205,7 +2205,7 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.33",
     [[
-        SELECT RTRIM(X'004100', X'0042');
+        SELECT TRIM(TRAILING X'0042' FROM X'004100');
     ]], {
         -- <func-22.33>
         "\0A"
@@ -2215,13 +2215,44 @@ test:do_execsql_test(
 test:do_execsql_test(
     "func-22.34",
     [[
-        SELECT RTRIM(X'00004100420000', X'00');
+        SELECT TRIM(TRAILING X'00' FROM X'00004100420000');
     ]], {
         -- <func-22.34>
         "\0\0A\0B"
         -- </func-22.34>
     })
 
+-- gh-3879 Check BOTH.
+
+test:do_execsql_test(
+    "func-22.35",
+    [[
+        SELECT TRIM(BOTH FROM '  hi  ');
+    ]], {
+        -- <func-22.35>
+        "hi"
+        -- </func-22.35>
+    })
+test:do_execsql_test(
+    "func-22.36",
+    [[
+        SELECT TRIM(BOTH 'xyz' FROM '  hi  ');
+    ]], {
+        -- <func-22.36>
+        "  hi  "
+        -- </func-22.36>
+    })
+
+test:do_execsql_test(
+    "func-22.37",
+    [[
+        SELECT TRIM(BOTH 'xyz' FROM 'xyxzy  hi  zzzy');
+    ]], {
+        -- <func-22.37>
+        "  hi  "
+        -- </func-22.37>
+    })
+
 -- This is to test the deprecated sql_aggregate_count() API.
 --
 --test:do_test(
@@ -2838,16 +2869,16 @@ test:do_execsql_test(
     "SELECT TRIM(CHAR(32,00,32,00,32));",
     {string.char(00,32,00)})
 
--- LTRIM
+-- LEFT TRIM
 test:do_execsql_test(
     "func-70",
-    "SELECT LTRIM(CHAR(32,00,32,00,32));",
+    "SELECT TRIM(LEADING FROM CHAR(32,00,32,00,32));",
     {string.char(00,32,00,32)})
 
--- RTRIM
+-- RIGHT TRIM
 test:do_execsql_test(
     "func-71",
-    "SELECT RTRIM(CHAR(32,00,32,00,32));",
+    "SELECT TRIM(TRAILING FROM CHAR(32,00,32,00,32));",
     {string.char(32,00,32,00)})
 
 -- GROUP_CONCAT
diff --git a/test/sql-tap/with1.test.lua b/test/sql-tap/with1.test.lua
index f1a1699637d1..5f26f1141d3a 100755
--- a/test/sql-tap/with1.test.lua
+++ b/test/sql-tap/with1.test.lua
@@ -550,7 +550,7 @@ test:do_execsql_test("8.1-mandelbrot", [[
       SELECT group_concat( substr(' .+*#', 1+min(iter/7,4), 1), '') 
       FROM m2 GROUP BY cy
     )
-  SELECT group_concat(rtrim(t),x'0a') FROM a;
+  SELECT group_concat(trim(TRAILING FROM t),x'0a') FROM a;
 ]], {
   -- <8.1-mandelbrot>
   [[                                    ....#