diff --git a/applications/utilities/miscellaneous/foamDictionary/foamDictionary.C b/applications/utilities/miscellaneous/foamDictionary/foamDictionary.C
index 3644f45a89..42af8f5017 100644
--- a/applications/utilities/miscellaneous/foamDictionary/foamDictionary.C
+++ b/applications/utilities/miscellaneous/foamDictionary/foamDictionary.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2016-2020 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2016-2021 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -56,7 +56,10 @@ Usage
         Adds the entry (should not exist yet)
 
       - \par -set \<value\>
-        Adds or replaces the entry or applies a list of substitutions
+        Adds or replaces the entry selected by \c -entry
+
+      - \par -set \<substitutions\>
+        Applies the list of substitutions
 
       - \par -merge \<value\>
         Merges the entry
@@ -134,6 +137,11 @@ Usage
         dictionary with keyword 'entryDDD' where DDD is the position
         in the dictionary (after ignoring the FoamFile entry).
 
+      - Substitute multiple entries:
+        \verbatim
+          foamDictionary system/controlDict -set "startTime=2000, endTime=3000"
+        \endverbatim
+
 \*---------------------------------------------------------------------------*/
 
 #include "argList.H"
@@ -267,19 +275,9 @@ void remove(dictionary& dict, const dictionary& removeDict)
 
 void substitute(dictionary& dict, string substitutions)
 {
-    // Add '()' delimiters to the substitutions if not present
-    const string whitespace(" \t");
-    string::size_type last = substitutions.find_last_not_of(whitespace);
-    if (substitutions[last] != ')')
-    {
-        substitutions = '(' + substitutions + ')';
-    }
-
-    word funcName;
     wordReList args;
     List<Tuple2<word, string>> namedArgs;
-
-    dictArgList(substitutions, funcName, args, namedArgs);
+    dictArgList(substitutions, args, namedArgs);
 
     forAll(namedArgs, i)
     {
diff --git a/src/OpenFOAM/db/dictionary/dictionary.C b/src/OpenFOAM/db/dictionary/dictionary.C
index acd5cbc400..86214dab3e 100644
--- a/src/OpenFOAM/db/dictionary/dictionary.C
+++ b/src/OpenFOAM/db/dictionary/dictionary.C
@@ -1699,6 +1699,83 @@ void Foam::dictArgList
 }
 
 
+void Foam::dictArgList
+(
+    const string& funcArgs,
+    wordReList& args,
+    List<Tuple2<word, string>>& namedArgs
+)
+{
+    int argLevel = 0;
+    bool namedArg = false;
+    word argName;
+
+    word::size_type start = 0;
+    word::size_type i = 0;
+
+    for
+    (
+        word::const_iterator iter = funcArgs.begin();
+        iter != funcArgs.end();
+        ++iter
+    )
+    {
+        char c = *iter;
+
+        if (c == '(')
+        {
+            ++argLevel;
+        }
+        else if (c == ',' || std::next(iter) == funcArgs.end())
+        {
+            if (std::next(iter) == funcArgs.end())
+            {
+                if (c == ')')
+                {
+                    --argLevel;
+                }
+
+                ++i;
+            }
+
+            if (argLevel == 0)
+            {
+                if (namedArg)
+                {
+                    namedArgs.append
+                    (
+                        Tuple2<word, string>
+                        (
+                            argName,
+                            funcArgs(start, i - start)
+                        )
+                    );
+                    namedArg = false;
+                }
+                else
+                {
+                    args.append(wordRe(funcArgs(start, i - start)));
+                }
+                start = i+1;
+            }
+        }
+        else if (c == '=')
+        {
+            argName = funcArgs(start, i - start);
+            string::stripInvalid<variable>(argName);
+            start = i+1;
+            namedArg = true;
+        }
+        else if (c == ')')
+        {
+            --argLevel;
+        }
+
+        ++i;
+    }
+}
+
+
 Foam::Pair<Foam::word> Foam::dictAndKeyword(const word& scopedName)
 {
     string::size_type i = scopedName.find_last_of
diff --git a/src/OpenFOAM/db/dictionary/dictionary.H b/src/OpenFOAM/db/dictionary/dictionary.H
index 8eec08877b..d2ae911bd9 100644
--- a/src/OpenFOAM/db/dictionary/dictionary.H
+++ b/src/OpenFOAM/db/dictionary/dictionary.H
@@ -748,6 +748,14 @@ void dictArgList
     List<Tuple2<word, string>>& namedArgs
 );
 
+//- Parse dictionary substitution argument list
+void dictArgList
+(
+    const string& funcArgs,
+    wordReList& args,
+    List<Tuple2<word, string>>& namedArgs
+);
+
 //- Extracts dict name and keyword
 Pair<word> dictAndKeyword(const word& scopedName);