diff --git a/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.C b/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.C
index d6c4f935d6..aad851509e 100644
--- a/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.C
+++ b/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.C
@@ -147,7 +147,7 @@ ${typeName}FvOption${SourceType}::addSup
         Info<< "${typeName}FvOption${SourceType}::addSup()\n";
     }
 
-//{{{ begin code
+//{{{ begin code - warn/fatal if not implemented?
     ${codeAddSup}
 //}}} end code
 }
@@ -163,11 +163,11 @@ ${typeName}FvOption${SourceType}::addSup
 {
     if (${verbose:-false})
     {
-        Info<< "${typeName}FvOption${SourceType}::addSup()\n";
+        Info<< "${typeName}FvOption${SourceType}::addSup(rho)\n";
     }
 
-//{{{ begin code
-    ${codeAddSup}
+//{{{ begin code - warn/fatal if not implemented?
+    ${codeAddSupRho}
 //}}} end code
 }
 
diff --git a/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.H b/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.H
index e252336236..b38b4e92f6 100644
--- a/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.H
+++ b/etc/codeTemplates/dynamicCode/codedFvOptionTemplate.H
@@ -35,7 +35,14 @@ Description
 
     codeAddSup
     (
-        fvMatrix<Type}>& eqn,
+        fvMatrix<Type>& eqn,
+        const label fieldi
+    )
+
+    codeAddSupRho
+    (
+        const volScalarField& rho,
+        fvMatrix<Type>& eqn,
         const label fieldi
     )
 
diff --git a/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.C b/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.C
index 2a6a25d5aa..f83e260887 100644
--- a/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.C
+++ b/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.C
@@ -100,6 +100,12 @@ bool Foam::dynamicCodeContext::valid() const noexcept
 }
 
 
+const Foam::entry* Foam::dynamicCodeContext::findEntry(const word& key) const
+{
+    return this->dict().findEntry(key, keyType::LITERAL);
+}
+
+
 bool Foam::dynamicCodeContext::readEntry
 (
     const word& key,
diff --git a/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.H b/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.H
index 91e4441337..95f527dd12 100644
--- a/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.H
+++ b/src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCodeContext.H
@@ -176,6 +176,9 @@ public:
 
     // Reading
 
+        //- Locate literal dictionary entry, nullptr if not found
+        const entry* findEntry(const word& key) const;
+
         //- Read string entry from context dictionary
         //- append content to SHA1 hashing and add line number etc.
         //
diff --git a/src/fvOptions/sources/general/codedSource/CodedFvSource.C b/src/fvOptions/sources/general/codedSource/CodedFvSource.C
index 969cb79374..1799249345 100644
--- a/src/fvOptions/sources/general/codedSource/CodedFvSource.C
+++ b/src/fvOptions/sources/general/codedSource/CodedFvSource.C
@@ -79,9 +79,30 @@ void Foam::fv::CodedSource<Type>::prepare
 
     //dynCode.removeFilterVariable("code");
     dynCode.setFilterVariable("codeCorrect", codeCorrect_);
-    dynCode.setFilterVariable("codeAddSup", codeAddSup_);
     dynCode.setFilterVariable("codeConstrain", codeConstrain_);
 
+    // Missing codeAddSup or codeAddSupRho handled on input,
+    // but also check for empty() and inject "NotImplemented" to avoid
+    // cases where the user has specified or used the wrong one
+    // (ie, compresssible vs incompressible)
+
+    if (codeAddSup_.empty())
+    {
+        dynCode.setFilterVariable("codeAddSup", "NotImplemented");
+    }
+    else
+    {
+        dynCode.setFilterVariable("codeAddSup", codeAddSup_);
+    }
+    if (codeAddSupRho_.empty())
+    {
+        dynCode.setFilterVariable("codeAddSupRho", "NotImplemented");
+    }
+    else
+    {
+        dynCode.setFilterVariable("codeAddSupRho", codeAddSupRho_);
+    }
+
     // Compile filtered C template
     dynCode.addCompileFile(codeTemplateC);
 
@@ -154,7 +175,18 @@ bool Foam::fv::CodedSource<Type>::read(const dictionary& dict)
     auto& ctx = codedBase::codeContext();
 
     ctx.readEntry("codeCorrect", codeCorrect_);
-    ctx.readEntry("codeAddSup", codeAddSup_);
+
+    // Need one or both codeAddSup/codeAddSupRho.
+    // - do precheck and let the usual mechanism fail
+
+    const bool mandatory =
+    (
+        !ctx.findEntry("codeAddSup")
+     && !ctx.findEntry("codeAddSupRho")
+    );
+
+    ctx.readEntry("codeAddSup", codeAddSup_, mandatory);
+    ctx.readEntry("codeAddSupRho", codeAddSupRho_, mandatory);
 
     // ctx.readEntry("codeConstrain", codeConstrain_);
     ctx.readEntry  // Compatibility
@@ -233,7 +265,7 @@ void Foam::fv::CodedSource<Type>::addSup
 {
     DebugInfo
         << "fv::CodedSource<" << pTraits<Type>::typeName
-        << ">::addSup for source " << name_ << endl;
+        << ">::addSup(rho) for source " << name_ << endl;
 
     updateLibrary(name_);
     redirectOption().addSup(rho, eqn, fieldi);
diff --git a/src/fvOptions/sources/general/codedSource/CodedFvSource.H b/src/fvOptions/sources/general/codedSource/CodedFvSource.H
index 2f1606df96..8bb4114f77 100644
--- a/src/fvOptions/sources/general/codedSource/CodedFvSource.H
+++ b/src/fvOptions/sources/general/codedSource/CodedFvSource.H
@@ -43,13 +43,20 @@ Description
 
     codeAddSup
     (
-        fvMatrix<Type}>& eqn,
+        fvMatrix<Type>& eqn,
+        const label fieldi
+    )
+
+    codeAddSupRho
+    (
+        const volScalarField& rho,
+        fvMatrix<Type>& eqn,
         const label fieldi
     )
 
     codeConstrain
     (
-        fvMatrix<Type}>& eqn,
+        fvMatrix<Type>& eqn,
         const label fieldi
     )
     \endverbatim
@@ -141,6 +148,7 @@ protected:
 
         string codeCorrect_;
         string codeAddSup_;
+        string codeAddSupRho_;
         string codeConstrain_;
 
         //- Underlying code