diff --git a/docs/guide/simulating.rst b/docs/guide/simulating.rst
index 5758af4d3..1abd93a11 100644
--- a/docs/guide/simulating.rst
+++ b/docs/guide/simulating.rst
@@ -166,11 +166,6 @@ Unfortunately, using the optimizer with SystemC files can result in
 compilation taking several minutes. (The SystemC libraries have many little
 inlined functions that drive the compiler nuts.)
 
-If using your own makefiles, you may want to compile the Verilated
-code with ``--MAKEFLAGS -DVL_INLINE_OPT=inline``. This will inline
-functions; however, this requires that all cpp files be compiled in a single
-compiler run.
-
 You may uncover further tuning possibilities by profiling the Verilog code.
 See :ref:`profiling`.
 
diff --git a/include/verilatedos.h b/include/verilatedos.h
index 0a1df2035..2049eb0cf 100644
--- a/include/verilatedos.h
+++ b/include/verilatedos.h
@@ -312,8 +312,10 @@
 //=========================================================================
 // Optimization
 
-#ifndef VL_INLINE_OPT
-# define VL_INLINE_OPT  ///< "inline" if compiling all objects in single compiler run
+#ifndef VL_NO_LEGACY
+# ifndef VL_INLINE_OPT
+#   define VL_INLINE_OPT  // Historical, has no effect on Verilated models.
+# endif
 #endif
 
 //=========================================================================
diff --git a/src/V3AstNodeOther.h b/src/V3AstNodeOther.h
index 252983cdb..6aeef4f1f 100644
--- a/src/V3AstNodeOther.h
+++ b/src/V3AstNodeOther.h
@@ -534,7 +534,6 @@ class AstCFunc final : public AstNode {
                          // an explicitly passed 'self' pointer as the first argument.  This can
                          // be slightly faster due to __restrict, and we do not declare in header
                          // so adding/removing loose functions doesn't recompile everything.
-    bool m_isInline : 1;  // Inline function
     bool m_isVirtual : 1;  // Virtual function
     bool m_entryPoint : 1;  // User may call into this top level function
     bool m_dpiPure : 1;  // Pure DPI function
@@ -564,7 +563,6 @@ public:
         m_isDestructor = false;
         m_isMethod = true;
         m_isLoose = false;
-        m_isInline = false;
         m_isVirtual = false;
         m_needProcess = false;
         m_entryPoint = false;
@@ -606,7 +604,6 @@ public:
     void rtnType(const string& rtnType) { m_rtnType = rtnType; }
     bool dontCombine() const { return m_dontCombine || isTrace() || entryPoint(); }
     void dontCombine(bool flag) { m_dontCombine = flag; }
-    bool dontInline() const { return dontCombine() || slow() || funcPublic(); }
     bool declPrivate() const { return m_declPrivate; }
     void declPrivate(bool flag) { m_declPrivate = flag; }
     bool keepIfEmpty() const VL_MT_SAFE { return m_keepIfEmpty; }
@@ -628,8 +625,6 @@ public:
     bool isLoose() const { return m_isLoose; }
     void isLoose(bool flag) { m_isLoose = flag; }
     bool isProperMethod() const { return isMethod() && !isLoose(); }
-    bool isInline() const { return m_isInline; }
-    void isInline(bool flag) { m_isInline = flag; }
     bool isVirtual() const { return m_isVirtual; }
     void isVirtual(bool flag) { m_isVirtual = flag; }
     bool needProcess() const { return m_needProcess; }
diff --git a/src/V3Branch.cpp b/src/V3Branch.cpp
index aa6966f96..5cbc7e7ca 100644
--- a/src/V3Branch.cpp
+++ b/src/V3Branch.cpp
@@ -56,11 +56,6 @@ class BranchVisitor final : public VNVisitorConst {
         }  // else leave unknown
     }
 
-    void visit(AstCFunc* nodep) override {
-        if (!nodep->dontInline()) nodep->isInline(true);
-        iterateChildrenConst(nodep);
-    }
-
     void visit(AstNode* nodep) override {
         if (nodep->isUnlikely()) {
             UINFO(4, "  UNLIKELY: " << nodep);
diff --git a/src/V3EmitCFunc.h b/src/V3EmitCFunc.h
index e83e30127..2ed257146 100644
--- a/src/V3EmitCFunc.h
+++ b/src/V3EmitCFunc.h
@@ -334,7 +334,6 @@ public:
         puts("\n");
         m_lazyDecls.emit(nodep);
         if (nodep->ifdef() != "") putns(nodep, "#ifdef " + nodep->ifdef() + "\n");
-        if (nodep->isInline()) putns(nodep, "VL_INLINE_OPT ");
         emitCFuncHeader(nodep, m_modp, /* withScope: */ true);
 
         if (nodep->isConstructor()) {